Evans, R (on the application of) v Governor HM Prison Brockhill [1998] EWCA Civ 1042

EWCA-Civ
Evans, R (on the application of) v Governor HM Prison Brockhill
[1998] EWCA Civ 1042 · 1998-06-19
MR B EMMERSON and MR P WEATHERBY (Instructed by Messrs Graysons, Sheffield, S1 1TD (London Agents: Messrs Kingsford Stacey, London WC2A 3UB)) appeared on behalf of the Appellant.MR P SALES and MR M FORDHAM (Instructed by The Treasury Solicitors, London SW1H 9JS) appeared on behalf of the Respondent

- - - - - -

J UDGMENT

( As approved by the Court )

- - - - - -

© Crown Copyright

JUDGMENT

LORD WOOLF, MR: This is an appeal from a judgment of Collins J. given on the 10th of June l997. Collins J. dismissed a claim for damages for false imprisonment made by the appellant, Michelle Carol Evans, against the Governor of Brockhill Prison. The claim for damages was included in a joint application for leave to apply for judicial review and habeas corpus which was made on the 6th of September l996. The appeal raises issues of importance involving two principles which are deeply embedded in our law. The first is that any authoritative decision of the courts stating what is the law operates retrospectively. The decision does not only state what the law is from the date of the decision, it states what it has always been. This is the position even if in setting out the law the court overrules an earlier decision which took a totally different view of the law. The second principle is that a person imprisoned without lawful authority is entitled to damages irrespective of any question of fault on the part of the person responsible for the imprisonment.

The Background to the Claim

The applications for judicial review and habeas corpus were made while the appellant was a prisoner at Brockhill Prison. She was in prison after being sentenced on the 12th of January l996 to two years imprisonment for robbery, to nine months imprisonment concurrent for two offences of burglary and to three months imprisonment concurrent for assault occasioning actual bodily harm.On the 15th of November l996 the Divisional Court, [1997] Q.B. 443, (Bingham of Cornhill C.J., Rose L.J. and Blofeld J.) made no order on the appellant's motion for habeas corpus, allowed her application for judicial review and declared that the appellant’s conditional release date from prison, as correctly calculated, should have been the 17th of September l996 (taking into account 19 days awarded for disciplinary offences). The appellant was released the same day, but that was 59 days later than she should have been released. It was for those 59 days additional imprisonment that she claimed damages. The Divisional Court, having given its decision, adjourned this claim for damages and it was this claim which Collins J. heard and dismissed.The Divisional Court also certified that a point of law of general public importance was involved in their decision, namely:
“What is the correct method of determining the ‘relevant period’ for the purposes of Section 41 of the Criminal Justice Act l991 and Section 67 of the Criminal Justice Act l967 in a case where an offender spent separate periods on remand in custody in respect of offences for which he is given concurrent sentences?”
but refused the Governor leave to appeal to the House of Lords. The appeal was not pursued.The appellant’s application to the court followed a decision of the Divisional Court in R v The Secretary of State for the Home Department, Ex Parte Naughton [l997] 1 WLR 118 given on the 4th of September l996. In Naughton the Divisional Court suggested that the method which was then being adopted for calculating the date of release of a short term prisoner, where the prisoner had been in prison on remand before being sentenced, was incorrect. The relevant statutory provisions are sections 33, 41, 51 of the Criminal Justice Act l991 and sections 67 and 104 Criminal Justice Act l967 as amended by the Police and Criminal Evidence Act l984. According to the method of calculation criticised in Naughton , the appellant’s release date would have been the 18th of November l996, (3 days after the decision of the Divisional Court in this case). This method of calculation followed the reasoning in a series of decisions of the Divisional Court, commencing with R v The Governor of Blundeston Prison, Ex Parte Gaffney [l982] 1 WLR 696. (All the relevant authorities are referred to in the Divisional Court’s judgment which is reported and it is not necessary to refer to them here). The short but by no means easy point which the Divisional Court had to determine was whether, when a person is sentenced to more than one period of imprisonment to be served concurrently, the period spent previously in custody on remand should be deducted from each particular sentence to which the period in remand relates before calculating the total sentence to be served, or whether such periods in custody should be aggregated and the release date calculated simply by deducting that aggregate from the total sentence. The decision in Gaffney had adopted the former solution while the Divisional Court in this case authoritatively decided that the latter solution provided the correct answer. As is confirmed by the facts of this case, which method of calculation is adopted can materially affect a prisoner's release date.The decisions which were disapproved of by the Divisional Court in this case set out how the release date should be calculated in unambiguous terms and it is accepted on this appeal that the Governor of Brockhill Prison had no alternative but to adopt the method of calculation laid down in the earlier decisions. He, therefore, had no reason to think that he was doing otherwise than complying with the law in detaining the appellant until the decision of the Divisional Court. It is not suggested that he had any discretion to release the appellant prior to the date calculated in accordance with the statutory provisions. It is common ground that he was not in any way personally at fault and that he could not have released the appellant earlier than he did.Nonetheless the position was one where, as the Divisional Court stated in its judgment in this case, “the construction previously put upon the legislative provisions, we have reviewed was wrong....that construction is capable of producing, and has, in some of the decided cases produced injustice”. It had, as the court states, resulted in a situation where “defendants are remaining in prison when the sentencing court did not intend that they should”. This is what has happened to the appellant. She should have been released on the 17th of September l996 and she was in fact released on the 15th of November l996. As Collins J recognised, the appellant “is one in respect of whom the practice has produced injustice, because she has served the period of 59 days more than she ought to have served, had the provisions of Section 67 been properly construed.” Yet he decided she was not entitled to damages for this period because the Governor was entitled to rely on the earlier decisions until they were held to be in error.It is to be noted that the effect of the error was not to alter the terms of the court order setting out the sentence. The error was limited to the manner in which that order was implemented.

The Case for the Appellant

It is the fact that the appellant was in prison longer than she should have been, which is the foundation of Mr Emmerson’s argument on behalf of the appellant. He submits, correctly, that the tort of false imprisonment has two ingredients, the fact of imprisonment and the absence of lawful authority to justify it. As Lord Bridge stated in Deputy Governor of Parkhurst Prison & Ors. Ex Parte Hague [l992] 1 A.C.58 at 162D:
“if A imposes upon B a restraint within defined bounds, and is sued by B for false imprisonment, the action will succeed or fail according to whether or not A can justify the restraint imposed on B as lawful.”
In the same case Lord Jauncey said much the same thing at 178C:

“Imprisonment is either lawful or false and questions of degree do not arise”

If the earlier cases had survived the Divisional Court’s decision in this case, then of course there would have been lawful justification. But Mr Emmerson submits that once the Divisional Court gave its decision it became apparent that there was no justification. He submits that the Divisional Court’s decision operates retrospectively so that the position as a matter of law is that the extra period of detention was never lawful. Mr Emmerson prays in aid the comment of Simon Brown L.J. in Percy v Hall [l996] QB 924 at 945:
“Clear it is that ordinarily a mistake of law, however understandable, cannot provide the lawful justification for an arrest where otherwise there is none”.
Mr Emmerson submits that there was no precedent for a governor in the position of the respondent in this case being granted immunity except by statute. If the imprisonment was unlawful that should be the end of the matter. He relies strongly on Articles 5(1) and(5) of the European Convention of Human Rights. He submits that to grant immunity to the Governor would be in clear conflict with Article 5(1) and (5) of the Convention.Although Mr Justice Collins dismissed the damages claim, in case the appellant should succeed on appeal, he assessed her damages in the sum of £2,000. Mr Emmerson submits that sum is far too low.

The Contentions On Behalf of The Governor

Not surprisingly, Mr Sales supports the reasoning of Mr Justice Collins. He accepts before this court that the Divisional Court's decision in this case must be treated as having retrospectively overruled the earlier cases. However he submits that until the decision of the Divisional Court in this case, the Governor was justified in applying the approach to the relevant statutory provisions which had specifically been laid down by the courts. The Governor did not make any mistake of law. He applied the law as laid down by the courts, as he was duty bound to do. The error of law was that of the courts in decisions prior to that of the Divisional Court. Ordinarily no claim of false imprisonment arises out of a decision of a court which is subsequently shown to have been erroneous and there is no reason here to hold the Governor responsible for simply obeying the courts. The Governor at the time that he continued to detain the appellant had no legal justification for doing other than he did. It was immaterial in the circumstances of this case that there was no direct court order. Collins J. therefore came to the correct decision.

The Authorities

Both Mr Sales and Collins J. relied heavily on the decision of this court in Percy v Hall . Although Mr Emmerson relied on the statement in the judgment of Simon Brown L.J. already quoted, the decision is undoubtedly helpful to the Governor. In Percy v Hall , the plaintiffs had brought an action for wrongful arrest and false imprisonment against constables who arrested them for breaching certain by-laws. In a trial of the preliminary issues, the Judge held the by-laws were invalid but that the invalidity did not preclude the constables from pleading lawful justification for making the arrests. This court, presided over by Simon Brown L.J., reversed the Judge’s decision as to the validity of the by-laws and also dismissed the plaintiff’s cross appeal as to the by-laws providing justification for the arrest.The approach of this court on the cross appeal, on the assumption the by-laws were invalid, was that whether the by-laws provided immunity should be determined at the time of the events about which complaint was made. At that time the by-laws were apparently and were in law presumed to be valid, and in the public interest needed to be enforced. This being the case, even if the by-laws were properly to be regarded as void for uncertainty, this would not deprive the constables of a defence of lawful justification, provided they could show that they had been acting in the reasonable belief that the plaintiffs were committing an offence against the by-laws.In giving the first judgment, Simon Brown L.J. referred to the House of Lords decision in Wills v Bowley [l983] 1 A.C. 57. This was a case which concerned a constable’s power of arrest under Section 28 of the Town Police Clauses Act l847, a section which required a constable to “take into custody without warrant, and forthwith convey before a Justice, any person who in his view” commits a range of offences. Lord Bridge of Harwich, in that case, stated at p.102:
“If a power of arrest in flagrante delicto is to be effective at all, the person who exercises it needs protection,....so far as the law can give it”.
The House of Lords held by a majority of 3 to 2 that section 28 of the 1847 Act protects the police, if they honestly but mistakenly believe on reasonable grounds that they have seen an offence being committed.

Lord Justice Simon Brown went on to say:

“This question, as it seems to me, falls to be answered as at the time of the events complained of. At that time these by-laws were apparently valid; they were in law to be presumed valid; in the public interest, moreover they needed to be enforced. It seems to me one thing to accept, as readily I do, that a subsequent declaration as to their invalidity operates retrospectively to entitle a person convicted of their breach to have their conviction set aside; quite another to hold that it transforms what, judged at the time, was to be regarded as the lawful discharge of the constables’ duty into what must later be found actionably tortious conduct.
I do not understand this point ever to have been addressed before. .... It is not covered by the general doctrine of restrospectivity with regard to the annulment of invalid instruments. I am not prepared to regard the many broad statements of principle as going this far.On the face of it, any right of redress on the part of those arrested under what ultimately are found to be defective by-laws should be against the Secretary of State as the maker of the invalid instrument. The Secretary of State is, indeed, here said to be liable on that ground. If however, as Mr Pleming recognises may well be the case, no such claim succeeds, essentially because English law provides no cause of action for invalid administrative action as such, that is no basis for creating a cause of action instead against those, here the defendant constables, who are not responsible for the invalidity. Nor is it good ground for denying them the common law defence of lawful justification which should surely be available to them. Quite the contrary. I see no sound policy reasons for making innocent constables liable in law, even though such liability would be under-written by public funds;"

(947-8)

Lord Justice Peter Gibson on this issue said he was in entire agreement with Simon Brown L.J. Schiemann L.J. also agreed. However, he considered the broader issue as to when a declaration that an enactment is invalid, takes effect. Does it take effect retroactively or only from the time of the court’s ruling? As to the second solution, Schiemann L.J. indicates that it has initial attractiveness. The law should never have been made and therefore one must proceed as though it never had been made. To do otherwise will in effect legalise the illegal and the courts are not in business to do that. Moreover, once the courts start to give some effect to illegal legislation, there will be less incentive for the legislature to refrain from such activity.Schiemann L.J. also points out the disadvantages of this approach. He says:
“Society cannot function if all legislation has first to be tested in court for legality. In practice, money will have been spent, taxes collected, businesses and property bought and sold and people arrested and perhaps imprisoned on the basis that what appears to be the law is the law”.

(p.951)

He added:
“It has been common place in our jurisprudence,....... to speak of a basic principle that an ultra vires enactment is void ab initio and of no effect. This beguilingly simple formulation, as is widely acknowledged, conceals more than it reveals. Manifestly in daily life an enactment will have had an effect in the sense that people will have regulated their conduct in the light of it. Even in the law courts it will often be found to have had an effect because the courts will have given a remedy to a person disadvantaged by the application of the ultra vires enactment to him or because a decision, binding on the parties thereto, has been rendered on the basis of the apparent law or because some period of limitation had expired making it too late now to raise any point on illegality.
The policy questions which the law must address in this type of case is whether any and if so what remedy should be given to whom against whom in cases where persons have acted in reliance on what appears to be valid legislation. To approach these questions by rigidly applying to all circumstances a doctrine that the enactment which has been declared invalid was “incapable of ever having had any legal effect on the rights or duties of the parties”, seems to me with all respect to the strong stream of authority in our law to that effect, needlessly to restrict possible answers which policy might require.”

(p.951)

Schiemann L.J. went on to point out that in the future our law might be developed in a similar way to that of European Community law where a considerable amount of flexibility has been shown in dealing with this question. It is, however, important to note that Schiemann L.J. was not referring to questions of retrospectivity of decisions elucidating the law.The only other recent decision to which it is necessary to refer is Olotu v Home Office [1997] 1 WLR 328 . In this case this court was concerned with the effect of the right to bail provided by section 4 of the Bail Act 1997 on a person who had been remanded in custody after the expiry of the custody time limit. This court decided that the expiry of the time limit did not render the custody unlawful but only gave a right to be released on bail. Accordingly until a court order had been made the custody was not unlawful and an action for damages could not succeed. The fact that the warrant in accordance with the required practice referred to the custody time limit did not alter the position. As the Lord Chief

Justice said in that case at p.334/5:

“She in any event, had no right to be released after 112 days; her right was to be released on bail by order of the court. Although alerted by the terms of the warrant to the date upon which the custody time limit was to expire, the governor had no independent role in making any application to the court, nor any authority to release the plaintiff without an order of the court”.
Lord Justice Mummery said very much the same at p.339. The Lord Chief Justice did say later on p335 that once the custody limit expired the plaintiff was “unlawfully detained” but he said this in the context of the plaintiff being obliged to order her release but until the court did so the governor being “neither entitled nor bound to release her.”Reliance was placed on the case of Henderson v Preston [1888] 21 QBD 362 but that case and the earlier case to which reference was made in the judgment of Lord Esher M.R. of Olliet v Bessy T. Jones Rep.214 are only authority for the proposition that a warrant “good on its face” can be relied upon by a gaoler until set aside and are no more than illustrations of the fact that until an order of a court is set aside it justifies detention so the imprisonment is not tortious. The same is true of Greaves v Keene [1879 ] 4 Exch D. 73

Conclusions

I readily endorse the approach of the Court of Appeal in Percy v Hall in relation to the facts which they were considering. In particular, I agree with Schiemann L.J. as to the need for flexibility when what appears on its face to be a perfectly valid by-law is declared invalid. I do not regard the recent decision of Boddington v British Transport Police [l998] 2 AER 203 as undermining authority of the decision in Percy v Hall . The only speech which could have such a consequence is that of Lord Irvine of Lairg, Lord Chancellor, but he did not refer to Percy v Hall. Lord Browne Wilkinson expressly reserved the question of its correctness and Lord Steyn's reasoning does not adversely reflect on its correctness.Percy v Hall cannot, however, be applied directly to the facts of this case. The application of the reasoning of the court in Percy v Hall to this case involves applying the reasoning to a different situation. In Percy v Hall the court were concerned as to whether a by-law although it was invalid could be given recognition, at least, to the extent of providing a defence to an action for false arrest. There is respectable, though still controversial, authority for regarding a by-law, like other executive and administrative decisions as being valid for some purposes until set aside. There is no similar authority for regarding a decision authoritatively overruled as still for some purposes setting out correctly what is the law. The situation is different from that where a prisoner is convicted and the conviction is subsequently set aside on appeal. Here the conviction is not retrospectively set aside by the higher court for all purposes. It can therefore provide lawful authority for imprisonment prior to it being set aside even though it has been shown to state inaccurately what is the law. This is the position if a court of record passes a sentence which is in excess of what the law allows on a defendant (for example a court only having power to pass nine months, passes a 12 months sentence where the mistake is found out afterwards and the sentence is subsequently quashed and a lawful sentence substituted). The Governor will be still entitled to rely on the fact of the sentence passed by the court as providing a justification for the imprisonment. The Governor is not required or entitled to assess for himself the validity of the sentence. He is entitled to assume that it is a valid sentence. However here the principle of retrospectivity has never applied, contrary to the position as to changes as to the interpretation of the law. Collins J. was therefore being far more radical than he acknowledges when he says (at page 16 of the transcript):
“It seems to me that the position here is not far from that. It is not on all fours, of course, because there is no direct court order, but there is what amounts to much the same thing, namely a court declaration as to how the Governor should approach his task of determining the length of the sentence to be served following the imposition of two years imprisonment overall by the Crown Court. The Governor was bound to calculate the correct term to be served in accordance with the provisions of Section 67 as construed by the court, because that was then the law. He did just that, and it seems to me, that it would be quite wrong for him, in those circumstances, to be liable in tort on the basis that he had no lawful justification for doing what he did. Indeed the contrary is surely the case, namely that he would have had no lawful justification for doing anything else.”
Looking at the matter from the point of view of the Governor, that may appear to be fair and reasonable. However, looking at the matter from the point of view of the appellant, the position is that, as everyone agrees, she has been wrongfully imprisoned and if this reasoning is correct, she has no right of redress. In addition the approach, as already indicated, is totally inconsistent with the principle of retrospectivity. The principle can be said to involve a fairytale, but it is a fairytale which is a long established foundation of judicial law making within our common law system and if it is to be undermined or weakened this should be left to the legislature or possibly the House of Lords.A difficulty with Collins J's approach is illustrated by asking: what would be the position if there are conflicting decisions of the courts of equal standing? What is the position of a governor until the law is clarified by a later decision? If a governor acts on advice which proves to be mistaken as to which decision correctly sets out the law does he have a defence? Mr Sales was prepared to concede he would not. But what if Collins J. is correct? What is the position if a governor by an oversight keeps a prisoner in custody for longer than he should on the basis of a binding decision, but contests the action for false imprisonment and on appeal it is established that the previous decision was wrongly decided with the result that the prisoner was not detained unlawfully on the correct interpretation of the law, is the governor to be held liable because of what was incorrectly thought to be the law at the time of the detention? The answer is surely that a governor would not be under any liability. But it is difficult to apply the principle of retrospectivity only when it is in the interest of a governor to do so. The correct answer is provided when it is remembered that fault is not an element of an action for false imprisonment and the sole question is whether the period in prison was as a matter of law justified or not. The sentence passed by the court was never in dispute. It was that sentence and that sentence alone which provided the Governor's justification. The dispute was as to how the law required the sentence to be calculated. As to this question of law the decision in the Divisional Court provided the correct answer. Collins J. was led in to error because he was looking at what was the just result, judged by the irrelevant consideration of the blameworthiness of the Governor.The approach of Collins J. involves extending the court’s approach of recognising for some purposes an executive or administrative act or a court order which has been quashed to the different situation where a court, having authority to do so, overrules an earlier decision of the courts so that the earlier decision no longer represents the law. Until the approach to the doctrine of precedent is changed, the practical consequence is that once the later decision has been given there is no right to rely on the earlier decision as correctly representing the law. For Collins J's approach to be justified there must be reliance on the fact of a court's decision rather than a statement as to what is the law made in reaching a decision. From the Governor's point of view, it is as though the earlier decision had not existed. This is an undoubtedly highly artificial result. It involves a fairytale. However as Mr Sales accepts it is not open to this court to abandon the fairytale. If the sentence cannot provide the justification, what the Governor is asking this court to do is to provide him with an immunity because of lack of fault but this is a task beyond the proper role of this court. It is inconsistent with the nature of the tort. In the case of Magistrates justification was provided by legislation in cases where they acted beyond their jurisdiction but it is not clear that Parliament would wish to interfere with the usual position here.At the start of his skeleton argument Mr Emmerson has put before the court a note on the case law in the United States on prospective overruling. This results in a much more flexible position than that which exists within this jurisdiction. It has much to commend it. In the field of administrative law there has been what I would regard as being some progress made in this area. The most notable illustration of this has been in conjunction with the grant of a declaration in public law proceedings. A particularly good example of this is provided by the case of R v The Panel On Take-overs and Mergers, ex parte Datafin [l987] QB 815. (See also Lewis “Retrospective and Prospective Rulings in Administrative Law” l987, Public Law pp 81 to 83). However what is involved here is a different situation. It is depriving an appellant of a right to damages which up until now she would receive as a right once it had been shown that the Governor had detained her contrary to law. The court did not purport to change and had no power to change the law for the future only. Although this could not be appreciated at the time of the false imprisonment the Governor did misapply the law, so that while he thought that the sentence justified the whole of the period of detention, it did not justify the extra 59 days. This is the position irrespective of any fault on the part of the Governor. Up to this case the consequence of a change in the law has been that the State in positions such as this has to bear the cost. It is by no means clear to me that this is not the just result where, albeit because of a mistaken view of the law based on decisions of the courts, individuals have been deprived of their liberty. Even if the Court had a discretion to deprive the appellant of her right to damages, I am not satisfied that it would be appropriate to exercise that discretion so as to do so. Any development of the law would, as Mr Emmerson contends, involve a contravention of Article 5(1) and (5) of the European Convention of Human Rights. (See Benham v United Kingdom (1996) 22 EHRR 293 ).The Benham case differed from this case in that it concerned a decision of Justices and, as already pointed out, a Magistrates Court is a Court of limited jurisdiction and in this respect differs from the High Court and the Crown Court. In the case of Justices, until the law was changed by Section 208 of the Court and Legal Services Act l990, so as to provide that there is no right to damages unless they acted in bad faith, Justices could be liable to pay damages if they acted in excess of jurisdiction. In Benham the Court found that the applicant who had been imprisoned for non payment of community charge had not been detained unlawfully as he would have been if the Magistrates had acted without jurisdiction. In these circumstances there was no contravention of Article 5(1) and in consequence Article 5(5) was not applicable (paragraph 50 at p.322). However, it is clear from the approach of the Court that if there had been a contravention of Article 5(1), then Article 5 would have required a right to compensation to comply with Article 5(5) of the Convention. The approach of the Court (and of the Commission) suggests, in addition, that if the sentence of imprisonment had been imposed without jurisdiction, then the immunity in relation to an action for damages granted by Section 108 of the Courts and Legal Services Act l989 would not have avoided a breach of Article 5(5) of the Convention. Mr Emmerson is therefore probably correct in submitting that if an imprisonment under domestic law is unlawful, a statutory immunity from liability will not be regarded under the Convention as excusing the failure to provide a remedy.The right to compensation contained in Article 5(5) is unqualified. When there is a bill before Parliament designed to bring the European Convention of Human Rights into our domestic law, it would not be desirable for the courts to establish a new head of immunity for the State which could well contravene Article 5(5).This case does reveal the need for an examination of our present approach to the retrospectivity of judicial decisions. The imminence of the arrival within our domestic law of the European Convention of Human Rights gives added urgency to that need. As it is, however, the conclusion which I have come to is that the appeal on liability from the decision of Collins J. should succeed and that the appellant should be granted the appropriate sum by way of damages.

Damages

In awarding £2000, Collins J. pointed out that there is singularly little help to be obtained from the authorities as to the correct amount to award in these circumstances. It is accepted by the appellant that this is not a case for an award of aggravated or exemplary damages. Nor are we concerned with special damages. The Judge accepted a submission on behalf of the Governor that there can be two elements to an award of damages for false imprisonment; the first being compensation for loss of liberty and the second being the damage to reputation, humiliation, shock, injury to feelings and so on which can result from the loss of liberty. In this case the second element is absent.The Judge was referred to two cases. The first, an unreported decision of the Court of Appeal Lunt v Liverpool City Justices , decided on 5th March l991 and the other Thompson v The Commissioner of Police of the Metropolis [l997] 2 AER 762.In the former case the Court of Appeal increased an award of £13,500 to £25,000 for a period of 42 days false imprisonment in respect of an alleged default in the payment of rates. While there is nothing significant about the circumstances in which the appellant lost his liberty in that case, the facts are very different from here. In Lunt the court was concerned with someone of good reputation and none of the imprisonment was justified. The experience was described by Lord Justice Bingham as “horrific” to a person of previous good character. The situation is also different from those considered by this court in Thompson . As a result of the period she was lawfully imprisoned, the appellant would have already made the necessary adjustments to serving a prison sentence. She was someone who had been properly sentenced to a term of two years imprisonment for serious criminal offending and until the court gave its decision in Naughton , she had no reason to think that she was not perfectly properly incarcerated.Collins J. declined to propose an amount for each extra day imprisoned. He considered that a global approach was correct. He was right in doing so. Mr Emmerson nonetheless pointed out that the sum of £2000 was the “equivalent of less than £35 per day” and was even lower than the daily figure contended for by the respondent. He suggested that as a guide for other cases, it would be useful for the court to indicate a daily or weekly amount so as to provide a guide for the many other cases which will also result from the Divisional Court's and our decisions in this case.We accept that an award of £2,000 is well below the appropriate figure for 59 extra days of imprisonment. We increase the award to £5,000. This is a global figure. We recognise that it is possible to work out a daily, weekly, or monthly figure from this amount for the approximately two months extra imprisonment of this case but we discourage such an exercise. No two cases are the same. The shorter the period the larger can be the pro rata rate. The longer the period the lower the pro rata rate. The length of sentence lawfully imposed is clearly similarly significant. The fact that the appellant was prepared to risk postponing her release date by committing disciplinary offences while in prison is also relevant.

LORD JUSTICE ROCH: Section 33 (1) of the Criminal Justice Act 1991 provides:

"As soon as a short term prisoner has served one half of his sentence, it shall be the duty of the Secretary of State .... (b) to release him on license if that sentence is for a term of 12 months or more."
A short term prisoner is a prisoner serving a sentence of less than 4 years; section 33 (5). Section 41 of the Act applies to any person whose sentence falls to be reduced under s.67 of the Criminal Justice Act 1967 by any relevant period within the meaning of that section (Section 41(1)). Section 41(2) provides:
"For the purpose of determining for the purposes of this part (a) whether a person to whom this section applies has served one half ..... of his sentence ...... the relevant period shall, subject to sub-section (3) below, be treated as having been served by him as part of that sentence."
Section 42 of the Act enables prison rules to be made which include provision for the award of additional days in custody for short term prisoners who are guilty of disciplinary offences. Sub-section (2) of that section provides:
"Where additional days are awarded to a short term .... prisoner .... and are not remitted in accordance with prison rules .... (a) Any period which he must serve before becoming entitled to or eligible for release under this part .... shall be extended by the aggregate of those additional days."
Section 67(1) of the Criminal

Justice Act 1967 provides:

"The length of any sentence of imprisonment imposed on an offender by a court shall be treated as reduced by any relevant period ...."
Section 67(1A) defined the meaning of “relevant period”. It is not necessary to set out the terms of that sub-section. It suffices to say that there was uncertainty as to the meaning of that sub-section, which was inserted into the 1967 Act by section 49 of the Police and Criminal Evidence Act 1984, where a prisoner had been sentenced to serve a number of concurrent sentences of imprisonment for different offences and had spent separate periods on remand in custody in respect of two or more of those offences prior to being sentenced.The interpretation of the sub-section’s predecessor came first before the Divisional Court in R -v- Governor of Blundeston Prison ex parte Gaffney [1982] 1 WLR 696. The Divisional Court consisting of Lord Lane, Chief Justice, Lloyd and Eastham JJ decided that that sub-section was to be construed so that Gaffney’s period in prison should be calculated by reducing the period which he had to serve in respect of the offence for which he received the longest of the concurrent sentences by the time spent on remand in custody in respect of that offence. The fact that he had spent other periods in custody on remand in respect of other offences was to be ignored in calculating his date of release. The leading judgment was given by Eastham J with whom Lloyd J as he then was agreed. Lord Lane CJ added:
"It may be that the result appears to be unjust, but it is a result which we are forced to achieve by reason of the wording of the Act."
The matter came before the Divisional Court again in R -v- Secretary of State for the Home Office ex parte Read [1987] 9 Cr App R (S) 206 following the insertion of sub-section (1A) into s. 67. The court, although not apparently referred to the case of Gaffney reached the same practical result. Those decisions were followed by another Divisional Court in R -v- Governor of HM Prison Styal ex parte Mooney [1996] 1 Cr App R (S) 74. In that case it was said to be the practice of sentencing courts to avoid potential injustice by taking into account time spent on remand in custody in respect of the offences for which shorter terms of imprisonment were imposed when arriving at the period appropriate for the offence in respect of which the longest period of imprisonment was passed.On the 12th January of 1996 the applicant in these proceedings was sentenced at Cardiff Crown Court to a total of two years imprisonment. She was sentenced for four offences: robbery - 2 years imprisonment, two burglaries - 9 months imprisonment on each, and assault occasioning actual bodily harm - 3 months imprisonment. All those sentences were ordered to run concurrently. The applicant had spent two days in police custody in respect of the first of the burglaries. She spent 60 days in custody in respect of the second of the burglaries. Finally she spent 73 days on remand in prison in respect of the robbery. The date on which the Secretary of State was under a duty to release the applicant with the “relevant period” being calculated in accordance with the interpretation of s. 67 of the 1967 Act pronounced by the Divisional Court on at least three occasions prior to the date on which the applicant was sentenced was the 18th of November 1996. On the 4th of September 1996 the Divisional Court consisting of Simon Brown LJ and Popplewell J gave judgment in R -v- Secretary of State for the Home Department ex parte Naughton [1997] 1 WLR 118 . In that case the applicant, who had been sentenced to consecutive terms of imprisonment, sought to argue that the periods spent on remand in custody in relation to each offence should count against each of the consecutive sentences, submitting that that result was consistent with the reasoning of the Divisional Court in cases such as ex parte Gaffney . The Divisional Court rejected that submission on the basis that reading s. 67 so that it produced such a result would be an absurdity. In the course of his judgment Simon Brown LJ said:
"If that route is indeed thought difficult to reconcile with the ex parte Gaffney approach, so be it. Of one thing I am clear: whatever relevance (if any) we might have attached to s. 104(2) in ex parte Mooney .... had we known it remained in force had we been alive to the present argument, that is to say the consecutive sentence dimension to the case, I for my part would certainly not have described the language of s. 67 as “unambiguous” with regard to the correct treatment of concurrent sentence cases."
Popplewell J also expressed reservations about the correctness of the decisions on concurrent sentences.Three days later, on the 7th of September 1996 the applicant issued her application for judicial review claiming that the correct interpretation of s. 67 was that all periods spent on remand in custody should be taken into account as part of the relevant period in calculating the date by which she had served half of her sentence so that the duty to discharge her arose under s. 33 of the Act of 1991. The applicant had incurred 19 additional days under s. 42 of the Act, but taking into account the totality of the three periods she had spent in custody on remand her release date was the 17th of September.On the 29th of October 1996 the Divisional Court consisting of the Lord Chief Justice, Rose LJ and Blofeld J heard the appellant’s application and adopted the interpretation of s. 67(1A) of the 1967 Act for which the appellant’s counsel contended. The appellant in her application for judicial review sought not simply a declaration that her date of release was the 17th of September but also damages for false imprisonment. The Divisional Court made the declaration sought and adjourned the issue of damages. That issue came before Collins J on the 10th of June last year. Collins J decided:
"It seems to me that for the reasons that I have given, the Governor did have lawful justification or lawful cause for the imprisonment and was not guilty of the tort of false imprisonment. That being so, there is no basis for any claim for damages in the circumstances of this case and, accordingly, the applicant’s claim must fail."
This is an appeal against that decision. The argument of the appellant’s counsel is that the Divisional Court having declared that the appellant should have been released on the 17th of September 1996, her detention after that date was unlawful and in consequence, she is entitled to damages for false imprisonment. The fact of imprisonment is conceded as is the duty under s. 33(1) of the 1991 Act, no point being taken by the respondents that that duty is also a duty on the governor of the prison. All imprisonment is presumed to be false unless and until justified. The Governor cannot justify the imprisonment unless he can establish that it was in accordance with the law and that, in the light of the Divisional Court’s decision, he cannot do.Counsel for the appellant accepts that where a Court sentences a person to imprisonment but exceeds its powers, either because it has no power to send that person to detention or because the period of detention imposed exceeds the statutory maximum, the person has no action for false imprisonment because there is lawful justification for the detention, namely the court order. This is so even though the sentence is later overturned by the Court of Appeal Criminal Division on the grounds that it was unlawful or that part of it was unlawful. But says Mr Emmerson, the reason why the prison governor in those circumstances is not guilty of false imprisonment is that he is acting, in imprisoning the defendant, in pursuance of a warrant issued by a competent court and the law allows him to rely upon the warrant. The court is not guilty of the tort because it has an immunity. In the course of his submissions Mr Emmerson traced the development of the immunities that courts enjoy in this regard; the development of those immunities being different for courts of record and for other courts such as magistrates’ courts. It is not necessary in this judgment to set out those details.Mr Emmerson submits that the difference between such cases and the present is that in this case the validity and effect of the warrant in Miss Evans’s case expired on the 17th of September 1996 and with it the Governor’s justification for retaining Miss Evans in prison.Mr Emmerson directed our attention to Article 5 of the European Convention of Human Rights and in particular to paragraph (5) of that Article. His submission was that although the convention is not yet part of the law of England and Wales it will become so shortly. The Article and decisions of the European Court of Human Rights should guide this court towards its conclusion in this appeal. Article 5 provides:
"(1) Everyone has the right to liberty and security of person. No one shall be deprived of his liberty save in the following cases and in accordance with a procedure prescribed by law; (a) The lawful detention of a person after conviction by a competent court ........
(5) Everyone who has been the victim of arrest or detention in contravention of the provisions of this Article shall have an enforceable right to compensation."Mr Emmerson relies on the fact that Article 5 is the only Article to refer to an enforceable right to compensation as an indication that the Convention, as do the law and courts of this country, attaches particular importance to the liberty of the individual. The only way in which the Article can be read is that if the detention is not lawful the victim of the detention must have an enforceable right to compensation. Miss Evans’s detention after the 17th of September was unlawful and by analogy with Article 5 the law of this country must be and is that she has an enforceable right to compensation.The simple logic of the appellant’s case as advanced by Mr Emmerson is most attractive. The court has said that on the current reading of the section the appellant should have been released on the 17th of September 59 days before she was in fact released; therefore during these 59 days that she remained in prison, she was falsely imprisoned and is entitled to damages for that wrong that was done to her. The respondent’s case is that because on the reading of the section which the court has now pronounced to be the correct reading the appellant should have been released on the 17th of September, it does not follow that between the 17th of September and the 14th of November (the date on which she was actually released) there was no lawful justification for her imprisonment. The basis of the justification is the sentences totalling two years imprisonment passed by the Cardiff Crown Court on the 12th of January 1996. In calculating the date on which, according to the law, the appellant had to be released, the Governor had to apply the provisions of the 1991 Act and the 1967 Act. In applying those provisions, the Governor was bound to interpret them in accordance with authoritative decisions by competent courts, albeit those decisions were given in cases of prisoners other than the appellant.Mr Emmerson in his argument raised the question of what constitutes sufficient authority to justify a prison governor or other public servant acting upon it when deciding how he must exercise a statutory power or discharge a statutory duty. In my opinion it is not necessary to delay to consider that point in this case because it is clear that both at the date of the appellant’s sentence and on the 17th of September 1996 there was a substantial body of authority of the Divisional Court all of which pointed to one interpretation of s. 67, the interpretation applied by the Governor in Miss Evans’s case.On the 14th of November 1996 the Divisional Court interpreted the section in a different way. The respondents say that the fact that the Divisional Court has now pronounced to be the correct reading of the section, one that would have allowed for the appellant’s release on the 17th of September, it does not follow that between the 17th of September and the 14th of November there was no lawful justification for her imprisonment. The basic submission made by Mr Sales on behalf of the respondents is that the nature of the justification should be judged at the time of the detention complained of. Further, the mere fact that detention may later turn out to be false does not mean that the defence of lawful justification will not be available to a defendant such as a prison governor.With regard to Article 5 Mr Sales submits that there was no breach of Article 5 because up to the 14th of November 1996 Miss Evans’s detention was lawful, it following after conviction by a competent court. Alternatively victims of arrest or detention do have enforceable rights to compensation under the law of England and Wales, namely the tort of false imprisonment. Article 5(5) does not require that the right to compensation should be unqualified or unlimited. The right to compensation under our law is qualified by the defence of lawful justification and such defence is present in this case.This case raises issues which are difficult to resolve. On the one hand there is the principle of the liberty of the subject, to which our law attaches, rightly, great importance. On the other is the principle that public servants, be they government officials or local government officers, in exercising statutory powers or discharging statutory duties should read the provisions conferring those powers or imposing those duties in the way that the courts have decided they should be read. The legislature passes the statute. Where there is doubt as to its meaning or as to the limits or requirements of provisions those matters are determined by the courts and the members of the executive must apply those statutory provisions consistently with the decisions of the courts. That is an important constitutional principle. It would, submits Mr Sales, have been quite wrong for the governor of this prison to have adopted an interpretation of s. 67(1A) contrary to the decisions of the Divisional Court prior to the 14th of November 1996.It is common ground that the dilemma created by these two considerations cannot be resolved, at least by this court, by saying that the decision of the 14th November should not have retrospective effect. The fiction, well established in our law, is that when a court interprets a section in an Act of Parliament it is presumed that that section has had that meaning since its commencement date. There is a narrow but significant exception in the field of administrative law, where the court in its discretion can withhold an administrative law remedy where to grant it would lead to an undue interference in good administration.The resolution of this appeal depends upon the elements of the tort of false imprisonment. If a person is imprisoned and the only answer the gaoler has to a claim for damages based on the tort of false imprisonment is to prove that the detention was lawful then the appeal must succeed. However, if in some cases the gaoler can justify imprisonment although false so as to defeat the claim for compensation, and this is one of those cases, then the appeal fails. Does a gaoler have a defence of justification when he is acting on the authority of a warrant issued by a competent court, or in that situation does he have a bare immunity from suit provided the warrant correctly names the person detained and is still effective?The true position in the law of England and Wales is by no means clear, in my opinion, despite Mr Emmerson’s vigorous submission that it is. Halsbury’s Laws of England 4th Edition Volume 45 at paragraph 1338 deals with “justification” under the heading “Remedies and defences”. The text starts “The defendant in an action for false imprisonment is entitled to succeed if he pleads and proves that the imprisonment is legally justified”. In Hicks -v- Faulkner [1881] 8 QBD 167 Hawkins J said at page 170 when dealing with the recognised distinction between an action for malicious prosecution and an action for false imprisonment:
"That in false imprisonment the onus lies upon the defendant to plead and to prove affirmatively the existence of reasonable cause as his justification, whereas in an action for malicious prosecution the plaintiff must allege and prove affirmatively its non existence."
It is true that this observation was obiter but it is an indication that the defence of justification to an action for false imprisonment is not confined to establishing that the imprisonment is lawful. A case in which a wider defence of justification was permitted is that of Olliet -v- Bessey T. Jones Rep 214 followed by the Court of Appeal in Henderson -v- Preston [1888] 21 QBD 362 . Olliet was the gaoler. Bessey was the subject of a warrant issued by the Sheriff of Norfolk at the suit of one JS to the Bailiff of the Liberty of the Duke of Norfolk called Ailsham, which bailiff made his warrant to his deputies to arrest Bessey. Bessey was arrested out of the Liberty called Ailsham and was later carried into the Liberty and delivered to the gaoler Olliet, who was the gaoler for the Liberty. Olliet did not know that the arrest had been unlawful but detained Bessey in accordance with the warrant. It was held that no action lay against the gaoler for he had done no wrong to Bessey but had merely discharged his office which had not obliged him to enquire whether the original arrest had been tortious or not. Moreover it was held that even if Olliet had been informed that the first arrest was tortious his duty was nevertheless to detain Bessey, as Bessey had been delivered to him with a good warrant although the execution of it had been illegal; for if such information had been false and Olliet had let Bessey at large Olliet would have been liable to be sued for the escape. Bessey was not without remedy for he had a good action against those who had wrongly arrested him. Thus although the imprisonment was false the gaoler was able to justify it. The holding that it did not affect the gaoler’s position whether he knew or did not know that the initial arrest was tortious is consistent with fault not being an element of false imprisonment. The case also suggests that a gaoler has a special status. In Greaves -v- Keene [1879] 4 Exch D 73, compliance by a gaoler with an order of attachment of a solicitor for contempt defeated the solicitor’s claim for damages for false imprisonment, the gaoler keeping the plaintiff in custody for more than a year, in breach of s. 4 of the Debtors Act 1869 which provided:
"No person shall be imprisoned in any case excepted from the operation of this section for a period longer than one year."
The section itself provided that no person should be arrested or imprisoned for making default of payment of a sum of money with certain exceptions, one of which was default by an attorney or solicitor. Chief Baron Kelly did not consider that the gaoler had any obligation to enquire what contempt the plaintiff had committed or whether any statute dealing with the length of committal was being violated. Baron Pollock said:
"For the decision of this case it is sufficient to say that the defendant, in obedience to his duty under a warrant of the court, detained the plaintiff. The defendant is not by that warrant ordered to keep the plaintiff for any particular time or for any particular offence. The attachment is of a quasi criminal character and the only mode in which the defendant can obey it is by keeping the body of the plaintiff until the further order of the court."
Nevertheless the keeping of the plaintiff in prison for more than the 12 months permitted by Parliament must have rendered the imprisonment false yet the gaoler was still able to justify the prisoner’s detention by relying on the order of the court.In Henderson -v- Preston [supra] there was an issue as to whether the plaintiff had been detained in prison for one day more than the warrant of commitment permitted. He sued the governor of the prison. This court held:
"The governor of a prison is protected in obeying a warrant of commitment valid on the face of it, and an action for false imprisonment will not lay against him for the detention of a prisoner in pursuance of a terms of such warrant."
Lord Esher MR at page 366 said:
"That being the warrant, I adopt the judgment of Stephen J when he says that the warrant protects the governor and that no more need be said. In the case of Olliet -v- Bessey decided about 200 years ago, it was so held, and from that day to this no action can be found in the books to have been maintained against a gaoler where he acted within the terms of the warrant."
Lindley LJ said:
"What is a governor of a gaol who receives such a warrant to do except to obey it? ..... it appears to me that the governor by obeying that warrant has simply done his duty and the warrant protects him and is an answer to the action."
Thus if the warrant had resulted in the plaintiff being imprisoned for one day more than the permitted seven days, the governor could still justify the detention for that extra day by simply relying on the warrant. Again it would seem that the correct analysis is that the imprisonment would have been false but the governor would have been able to justify his detention of the plaintiff.There are two more recent cases: Olotu -v- Home Office and anr [1997] 1WLR 328 , a decision of the Court of Appeal presided over by the Lord Chief Justice, and Percy and anr -v- Hall and others [1997] QB 924 a decision of the Court of Appeal consisting of Simon Brown, Peter Gibson and Schiemann LJJ. In Percy -v- Hall the plaintiffs had been arrested on many occasions pursuant to various by-laws by constables acting in pursuance of those by-laws. The plaintiffs brought actions for wrongful arrest and false imprisonment against the constables who had arrested them. On a trial of preliminary issues Sir Peter Webster found that the by-laws were invalid but that their invalidity did not prevent the police from pleading lawful justification. On appeal by the defendants and cross-appeal by the plaintiffs this court allowed the defendant’s appeal stating that the by-laws were not invalid, they being sufficiently certain to be enforceable. This court went on to consider the cross-appeal although a decision on the cross-appeal was not strictly necessary. In his judgment Simon Brown LJ said at page 947 G:
"The central question raised here is whether these constables were acting tortiously in arresting the plaintiffs or whether instead they enjoy at common law a defence of lawful justification. This question, as it seems to me, falls to be answered as at the time of the events complained of. At that time these by-laws were apparently valid; they were in law presumed valid; in the public interest, moreover, they needed to be enforced. It seems to me one thing to accept, as readily I do, that a subsequent declaration as to their invalidity operates retrospectively to entitle a person convicted of their breach to have that conviction set aside; quite another to hold that it transforms what, judged at the time, was to be regarded as the lawful discharge of the constables’ duty into what must later be found actionably tortious conduct.
I do not understand this point ever to have been addressed before. In my judgment it is not covered by the general doctrine of retrospectivity with regard to the annulment of valid instruments. I am not prepared to regard the many broad statements of principle as going this far.On the face of it, any right of redress on the part of those arrested under what ultimately are found to be defective by-laws should be against the Secretary of State as the maker of the invalid instrument. The Secretary of State is, indeed, here said to be liable on that ground. If, however, as Mr Pleming recognises may well be the case, no such claim succeeds, essentially because English Law provides no cause of action for invalid administrative action as such, that is no basis for creating a cause of action against those, here the defendant constables, who are not responsible for the invalidity. Nor is it a good ground for denying them the common law defence of lawful justification which should surely be available to them. Quite the contrary. I see no sound policy reasons for making innocent constables liable in law, even though such liability would be underwritten by public funds."On this second issue Peter Gibson LJ expressed his entire agreement with Simon Brown LJ. Schiemann LJ agreed with both judgments. Again, it seems to me, that it is a necessary part of the views expressed by this court in that case that imprisonment under an invalid bylaw would be unlawful or false but the existence of the bylaw could still provide the arresting constable with justification so as to defeat the claim for damages.Finally in Olotu the plaintiff brought an action for false imprisonment against the Home Office for her detention at Pucklechurch Prison for 81 days without lawful authority, the time limit prescribed by the Prosecution of Offences (Custody Time Limits) Regulations 1987 (as amended) of 112 days having expired. The warrant under which the plaintiff had been held specified the expiry date of the 112 day period between committal and arraignment to which her detention was limited under s. 22 of the Prosecution of Offences Act 1985. The Home Office were successful in an application to strike out the action against them for false imprisonment as disclosing no reasonable cause of action. On an appeal by the plaintiff against that decision this court dismissed the appeal, despite the court being of the opinion that “once the custody time limit had expired the plaintiff was .... unlawfully detained”. See the judgment of the Lord Chief Justice page 335 C. The Lord Chief Justice went on to say:
"An order which would have led to her release could have been obtained either from the Crown Court or from the Divisional Court; but it does not follow that in the absence of any such order the Governor was guilty of falsely imprisoning the plaintiff and in my view he was neither entitled nor bound to release her."
Once again, it would seem, that although the 81 days imprisonment was false or unlawful, the prison governor and the Home Office were able to justify the fact of detention for that period. There the justification was that the plaintiff was in the custody of the Crown Court and only by order of that court could that period of custody be brought to an end. Once the custody time limit had expired without extension the Crown Court would have been obliged to order her release, albeit that that release would have been on bail and could have been the subject of conditions.That case can be distinguished from the present where there is no requirement that the court should intervene with a further order before the appellant could be released. Nevertheless the case is authority that the mere fact that the detention is unlawful does not result in the detainee being able to recover damages from the gaoler for the tort of false imprisonment. Moreover in that case the date on the warrant for release had passed.In the present case the warrant held by the governor of the prison was a warrant to detain the appellant in prison for a period of 2 years being the total of the four concurrent sentences. The governor was under a duty to release the appellant when she had served one half of her sentence; s. 33(1). To determine whether the appellant had served half of her sentence the relevant period had to be treated as having been served by the appellant. Additional days could be added on to extend the period of custody under s.42. The governor had a discretionary power to remit additional days. Consequently the date of release under s. 33(1) was not an absolute date. It was a date which could be affected by decisions made by the prison governor, although no doubt the prison governor had a duty under s. 42 not to act arbitrarily. In arriving at a release date of the 18th of November 1996, the governor applied the reading of s. 67 of the 1967 Act laid down by a number of decisions of the Divisional Court, the court competent to resolve disputes as to the meaning of that section. The respondent’s justification for detaining the appellant beyond the 17th of September was that he as a public servant was applying the relevant statutory provisions as interpreted by the courts. That in my judgment, was as much a duty for him as the duty of the prison governor in Olotu’s case to detain Mrs Olotu until the Crown Court made a further order. In my judgment there was nothing arbitrary about Miss Evans’s detention after the 17th of September. The defendant can and has justified it and this appeal should be dismissed.This being a view not shared by the other members of this court, the appropriate amount of damages has to be considered. On this part of the appeal, I agree with the Master of the Rolls that the figure assessed by Collins J is too modest and the award should be in the sum set out in his judgment.

LORD JUSTICE JUDGE:

On 12th January 1996, after being convicted of one robbery, two burglaries, and an assault occasioning actual bodily harm, Michelle Evans was sentenced to a total of 2 years’ imprisonment. Before sentence she had been held in remand in custody for separate periods of 62 days (on the burglary charge, which also included 60 days on the assault charge) and 73 days (on the robbery charge) an aggregate of 135 days. She was lawfully committed to prison to serve her sentence under section 12(1) of the Prison Act 1952.The discretionary aspects of earlier arrangements for remission and parole were altered by the Criminal Justice Act 1991 . As a “short term” prisoner within section 33 (5) of the 1991 Act, subject to the award of any additional days in custody for disciplinary offences, Michelle Evans was entitled to be released on licence as soon as she had served one half of the sentence imposed by the court. Therefore authorities such as Morris v Winter [1930] 1 KB 243, based on the principle that there was no entitlement to remission, cease to be relevant. Under section 41 of the 1991 Act the time that she had spent on remand counted towards the calculation of the period she should serve in prison. The sentence “fell to be reduced” by the “relevant period” within the meaning of section 67(1A) of the Criminal Justice Act 1967. In accordance with a series of decisions of the Divisional Court, both before and after the 1991 Act came into force, the governor of the prison in which she was serving her sentence did not calculate the period for which she should be detained after sentence had been imposed at the Crown Court by aggregating all the time she had spent on remand in custody.On 15th November 1996, having analysed each of these decisions, and considered a devastating criticism by Dr David Thomas, the distinguished editor of the Encyclopaedia of Current Sentencing Practice, of “grotesque deficiencies of the statutory framework of sentencing”, the Divisional Court, presided over by Lord Bingham CJ sitting with Rose LJ, Vice President of the Court of Appeal Criminal Division and Blofeld J, concluded that the correct construction of the relevant statutory provisions led inexorably to the conclusion that the earlier decisions of the Divisional Court were wrong, and that the total time spent on remand by Michelle Evans should be included within the “relevant period” prescribed by section 67(1A) of the 1967 Act. It has not been suggested on behalf of the governor that we should re-examine the most recent decision of the Divisional Court and it is accepted that the proper calculation of her sentence should have resulted in her release from custody on 17th September 1996. By that date she had completed the sentences imposed to punish her for her crimes. She was entitled to be released. In the result she remained in prison for 59 days longer than she should. This period of detention was unlawful.The governor was blameless. Indeed if he had not continued to detain her he would have been acting in defiance of the earlier decisions of the Divisional Court. He had, in the words of Lord Bingham “quite rightly founded” his practice on them. So in detaining her for as long as he did the Governor was responsibly performing his duties.The stark problem posed by this claim is whether an individual who has wrongfully spent 59 days longer in prison than she should is entitled to recover damages against the official responsible for continuing her detention by correctly applying legal principles as currently understood.The action for false imprisonment provides one of the important safeguards against unlawful deprivation of liberty. Although hallowed by usage, unless the word “false” is understood to mean wrongful or unlawful it is liable to mislead. To succeed with a claim for damages the plaintiff does not have to establish moral culpability or bad faith, which, as Taylor LJ observed in R v Deputy Governor of Parkhurst Prison & Others, Ex parte Hague [1992] 1 AC 58 , at p.123, “has never been a necessary ingredient” of the tort. So the present claim could not be defeated by the governor simply demonstrating good faith or even an honest but mistaken endeavour to perform his duties as he understood them. In the House of Lords Lord Bridge recognised two ingredients of the tort. “The fact of imprisonment and the absence of lawful authority to justify it...... The action will succeed or fail according to whether or not A can justify the restraint imposed on B as lawful”. Lord Jauncey cited with approval the definition of false imprisonment in Clerk & Lindsell on Torts 16th edition (1989) as “complete deprivation of liberty for any time, however short, without lawful cause”. Subsequently he said, at p.178:
"In my view, imprisonment is either lawful or false and questions of degree do not arise...... The definition of the tort .... is total deprivation of liberty, that is to say of all such liberty as the individual presently enjoys and not deprivation of total liberty, namely, liberty which is otherwise wholly unrestricted."
Accordingly, unless detention is lawful or justified, in the sense that it can be justified at law, it is wrongful. As Simon Brown LJ observed in Percy v Hall [1997] QB 924 at p. 945:
"Clear it is that ordinarily a mistake of law, however understandable, cannot provide the lawful justification ..... where otherwise there is none."
Mr Emmerson on behalf of the appellant suggested that once it was established that the detention was wrongful the claim for damages for false imprisonment should succeed.Section 12(1) of the Prison Act 1952 provides, so far as relevant “a prisoner, whether sentenced to imprisonment or committed to prison on remand or pending trial or otherwise, may be lawfully confined in any prison.”After the prisoner has been sentenced he is committed to prison and the governor lawfully holds him in custody (See Henderson v Preston [1888] 21 QBD 362 ). However the prisoner must be discharged immediately the sentence is finished. In Moone v Rose [1869] LR 4 QB 486 the plaintiff was committed to prison for contempt of court. The warrant was dated 3 November 1864. The relevant statute required the gaoler to bring her back to court “within 30 days”, failing which he was to discharge her. In fact the plaintiff was kept in custody until 5th June. Lush J observed
"The gaoler, therefore, having the plaintiff in custody, it was his duty to discharge her, and not having done so he is liable to an action..... In as much as the statute makes it imperative upon the gaoler to discharge the plaintiff, on his not having discharged her at the end of the specific time he is liable to be sued in trespass."
(See also Mee v Cruikshank [1902] 86 LT 708, where the right to immediate discharge following an acquittal was underlined.)On the other hand, even if the detention proves to be unlawful, provided an individual is in custody in obedience to an order of the court the governor is not liable to an action for false imprisonment. In effect the order of the court provides the necessary justification. This follows from the conclusion of Lord Bingham of Cornhill CJ in Olotu v Home Office and Another [1997] 1 WLR 328 when, after considering the provisions of the Prosecution of Offenders Act 1985 and the Prosecution of Offenders (Custody Time Limits) Regulations 1987 he said, at p.335
"Once the custody time limit had expired, the plaintiff was in my view unlawfully detained, and an order which would have led to her release could have been obtained either from the Crown Court or from the Divisional Court; but it does not follow that in the absence of any such order the governor was guilty of falsely imprisoning the plaintiff and in my view he was neither entitled or bound to release her."
Under the relevant statutory provisions the governor lacked any proper authority “to release the plaintiff without an order of the court”.Mummery LJ reached the same conclusion."Neither the regulations nor the provisions of the Prosecution of Offences Act 1985 absolved the governor of the prison from his duty to comply with the court’s direction in the warrant or varied that duty or conferred on him a power to discharge the plaintiff from custody immediately on or after the expiration of the custody time limit, in the absence of a court order......" (p.338)This decision underlined that a victim of unlawful custody would not necessarily succeed with a claim for damages for false imprisonment against the governor responsible for continuing the detention beyond the expiry of the statutory custody time limit. The governor in Olotu escaped liability because, notwithstanding that he personally was alerted to the expiry of the custody time limit, the legal effect of the order deprived him of any “authority to release” the prisoner without an order of the court. Olotu therefore confirms that even when a plaintiff establishes that he has undergone a period of unlawful detention his claim for damages may nevertheless fail.This is consistent with the protection provided for prison authorities who have detained a prisoner whose appeal against conviction is subsequently allowed or on whom a sentence in excess of jurisdiction has been ordered by the court. By way of illustration, in R v Preddy [1996] AC 875 the House of Lords allowed an appeal against conviction under section 15 of the Theft Act 1968 by over-ruling a long-standing decision of the Court of Appeal (R v Duru [1974] 1 WLR 2, followed in R v Mitchell [1993] CLR 788). Therefore the meaning of section 15 since it came into force was decided by the House of Lords in 1996. Those convicted and sentenced to imprisonment (including Duru himself) on the basis of the earlier incorrect construction of the section were however detained on the basis of the direct order of the court. Even if they could apply to have their convictions set aside (as to which see R v Hawkins [1997] 1 CAR 234: R v Graham [1997] 1 CAR 302) and ignoring any difficulties with limitation periods, any subsequent claim for damages for false imprisonment by them would be defeated by the simple application of the principle that the prison authorities had been acting in accordance with the order of the court. The same approach is illustrated in the decision of the European Court of Human Rights in Benham v United Kingdom [1996] 22 EHRR 293 where at p. 320 the court reiterated that:
"A period of detention will in principle be lawful if it is carried out pursuant to a court order. A subsequent finding that the court erred under domestic law in making the order will not necessarily retrospectively affect the validity of the intervening period of detention."
The question which therefore arises is whether the extended detention of Michelle Evans could be justified by the fact that the governor was precisely following the law relating to sentencing provisions as it was then, wrongly as it subsequently emerged, understood. No authority directly in point was cited, presumably because the present situation has never previously arisen, and prior to October 1992 and the coming into force of the 1991 Act, would have been met by the application of the principle in Morris v Winter. In effect the argument on behalf of the governor is that either as an application or a permissible extension of existing principle, in this unforeseen set of circumstances, the governor who applied the law as explained and laid down by the court was entitled to be protected from proceedings for false imprisonment in the same way as the governor in Olotu.During the course of argument there was some interesting discussion whether the effect of the decision of the Divisional Court on the 15th of November 1996 was prospective, in the sense that it was limited in its impact to subsequent events, or retrospective. As it was agreed that this important and difficult problem could not be resolved in the Court of Appeal, I shall merely note its application to the present case.In theory the law is not changed by a later decision of the Court which over-rules an earlier one. At the time when he made the appropriate calculation of the period for which Michelle Evans should be detained, the governor applied the earlier decisions of the court. If the most recent decision of the Divisional Court were to be regarded as prospective in its effect the claim against the governor could not succeed.In the context of subordinate legislation, the effect of a subsequent decision holding that the legislation was ultra vires was
"to render the instrument incapable of ever having had any legal effect upon the rights or duties of the parties to the proceedings .....(and) the application of the doctrine of precedent has the consequence of enabling the benefit of it to accrue to all other persons whose legal rights have been interfered with in reliance on the law which the statutory instrument purported to declare."
(Per Lord Diplock in Hoffmann-La Roche & Co v Secretary of State for Trade & Industry [1975] AC 295 at p.305: see also per Lord Irvine of Lairg LC in Boddington v British Transport Police [1998] 2 WLR 639 .) In Miliangos v Frank (Textiles) Limited [1976] AC 443 at p.490, Lord Simon expressed his concern about the decision to abrogate the judge-made rule in Re: United Railways of Havana and Regla Warehouses [1961] AC 1007, and summed up the principle in relation to judicial precedent:
"that the law must be deemed always to have been as my noble and learned friends now declare it."
Accordingly Preddy decided the meaning of section 15 of the Theft Act 1968 throughout the period from the time when it came into force as well as for the future. In the context of this case therefore, the decision of the Divisional Court simply corrected what must now be deemed to have been earlier misconceptions about the true meaning of section 67 of the 1967 Act. In Precedent in English Law (4th edition) at p.231 the authors explained the consequences by considering the impact of the decision in Hedley Byrne & Partners v Heller & Partners Limited [1964] AC 465 on Candler v Crane Christmas & Co [1951] 2 KB 164 which was held to have been wrongly decided. The authors observed
"the over-ruling of Candler’s case was no less retrospective than any other ruling. Someone who made a negligent mis-statement long before the Hedley Byrne decision could have been successfully sued the day after that decision, whereas he was previously under no tortious liability."
The authors went on to point out that the principle of retrospective over-ruling had been “accepted for upwards of 500 years”. This indeed seems to form the basis of the Practice Statement (Judicial Precedent) issued by the House of Lords in July 1966 [1966] 1 WLR 1234. Precedent was “an indispensable foundation upon which to decide” the law and its application to individual cases, providing as it does, some “degree of certainty”. Before deciding to depart from a previous decision the House would “bear in mind the danger of disturbing retrospectively” the basis on which citizens had conducted their civil affairs and “the especial need for certainty as to the criminal law”.For the present in this court we are bound to apply the theory - in R v National Insurance Commissioners, ex parte Hudson [1972] AC 944, at p.1026, Lord Simon spoke more robustly about a “pretence”, based at least in part on the centrality in our constitution of Parliamentary sovereignty - that the law was not changed by the decision of the Divisional Court on 15th November 1996. Therefore Michelle Evans’ continued detention was unlawful. The outcome of this appeal depends on whether the governor was legally justified in continuing her detention not on the basis of the order of the court (as in Olotu or Duru ) but because he adopted the method of calculating the effect of periods on remand promulgated by the earlier decisions of the Divisional Court.At least in the context of departmental circulars this question was left open by Taylor LJ in R v Deputy Governor, ex parte Hague , when at p.124, he said
"What is not clear is the validity or otherwise of acts done on the authority of or in obedience to the decision or order before it is struck down............ Would a prison governor obeying CI 10 / 1974 and prison officers carrying out his instructions thereunder be protected from civil actions if the circular is ultimately decided ultra vires and their decisions are quashed?"
This point did not arise for decision or attract further comment in the House of Lords.A not dissimilar problem was considered in Percy v Hall. The plaintiffs were arrested and detained under bye laws which for the purposes of argument were treated as invalid at the date of the arrests. It was argued on behalf of the plaintiffs that a mistake of law made in good faith by arresting officers did not provide them with a defence to an action for damages for wrongful arrest. Simon Brown LJ accepted as “hardly a controversial proposition” that when an ultra vires enactment such as a bye law was held to be void generally its effect was not prospective but retrospective. He then examined the submission on behalf of the constables that at the moment when they arrested the plaintiffs they were enforcing what appeared to be valid bye laws, or “the apparent law”: for them to have done otherwise would have been a dereliction of duty. The similarity between their position and that of the governor in the present case - “quite rightly” maintaining Michelle Evans in detention - was understandably underlined by Mr Sales.Simon Brown LJ identified and answered what he described as the central issue raised in the appeal at p.947:
"............ whether these constables were acting tortiously in arresting the plaintiffs or whether instead they enjoy at common law a defence of lawful justification. This question, as it seems to me, falls to be answered at the time of the events complained of. At that time these bye laws were apparently valid; they were in law to be presumed to be valid; in the public interest, moreover, they needed to be enforced. It seems to me one thing to accept, as readily I do, that a subsequent declaration as to their invalidity operates retrospectively to entitle a person convicted of their breach to have that conviction set aside; quite another to hold that it transforms what, judged at the time, was to be regarded as the lawful discharge of the constables’ duty into what must later be found actionably tortious conduct.
I do not understand this point ever to have been addressed before. In my judgment it is not covered by the general doctrine of retrospectivity with regard to the annulment of invalid instruments. I am not prepared to regard the many broad statements of principle as going this far."He concluded that the “common law defence of lawful justification ..... should surely be available to (the constables) ........ wherever they can show they were acting in the reasonable belief that the plaintiffs were committing a bye law offence”.Peter Gibson LJ expressed his “entire agreement” with this conclusion. Schiemann LJ, while explaining some of the reasons why the principle of retrospective effect of later decisions of the Court should be re-examined, also agreed. In effect, by analysing the situation confronting the constables at the time of the alleged wrongful arrest, they were exonerated from liability.Mr Emmerson argued that Percy v Hall should not be followed. First, Michelle Evans was detained on the basis of the Divisional Court’s earlier interpretation of section 67 of the 1967 Act, not a bye law subsequently approached as if it were invalid. The distinction he sought to draw does not undermine the conclusion that in meeting a claim for wrongful arrest the constables were able to rely on the existing state of the law at the time of arrest as providing proper justification for what would otherwise have been unlawful. Mr Emmerson further suggested that Percy v Hall was over-ruled in Boddington v British Transport Police . The House of Lords considered the validity of a bye law on which the prosecution was founded in the context of a criminal prosecution during the course of which the defendant had been deprived of any opportunity to argue against the validity of the bye law on which the prosecution was founded and concluded that he was entitled to advance this public law argument as part of his defence to criminal proceedings. Percy v Hall was cited and considered in the context of the argument about the retrospective or prospective effect of subsequent decisions. Bugg v DPP [1993] QB 473, followed in Percy v Hall on a different question - the invalidity of bye laws for uncertainty - was over-ruled. However on the question whether the police constables in Percy v Hall were entitled to rely on the principles of law established at the time of the arrest nothing relevant was said about the issues now under consideration save for a quotation by Lord Steyn of the observation of Lord Atkin in Eleko v Government of Nigeria [1931] AC 662 that
"no member of the executive can interfere with the liberty or property of a British subject except on condition that he can support the legality of his action before a court of justice."
Although I am unable to accept that Percy v Hall was over-ruled in Boddington Lord Atkin’s axiomatic statement of principle identifies the question which falls to be answered by the governor in the present case. The answer in reality is that Michelle Evans’ detention was believed to be legally justified by the state of the law as it was, erroneously, believed to be until the 15th of November 1996. Throughout the critical 59 day period although the governor was loyally making his calculation on the basis of the principles laid down in the earlier decisions of the Divisional Court he was in fact acting under a misapprehension about the correct method of calculation. The misconception on which his action was based has now been corrected. Applying the principle of retrospective over-ruling (which we are bound to do), although not in any way to blame, the governor was wrong in law. Therefore during the critical 59 days therefore the “legality” of his action cannot be supported.The main difficulty I have had with the present appeal is whether the governor should be in any less strong a position to meet a claim for damages for false imprisonment than the constables in Percy v Hall who unlawfully arrested citizens on the basis of bye laws which were subsequently declared to be invalid. He would have been in dereliction of his duties as governor if he had allowed Michelle Evans to leave prison before 15th November 1996. If she had escaped from custody on, say 10th October, as a prisoner unlawfully at large she would have been liable to arrest by police officers. If she had taken proceedings for false imprisonment against them after 15th November (by which date she would have established that she had not been unlawfully at large at all) they would perhaps have sought to rely on Percy v Hall to avoid liability.Depending on their own individual roles, and whether or not they themselves were acting lawfully, different persons responsible for detention may or may not be liable for damages for false imprisonment. Percy v Hall was concerned with arrest and detention after arrest, not detention after sentence under section 12(1) of the Prison Act 1952. It is already well established that the lawfulness of an arrest is not necessarily undermined by error on the part of an arresting police officer. This feature can be seen in Wills v Bowley [1983] 1 AC 57. On the basis of the proper meaning and construction of section 28 of the Town Police Clauses Act 1847 , it was decided by the House of Lords that a constable who honestly believed that an offence had been committed within his sight was entitled to exercise the power of arrest granted by section 28 without the arrest being invalidated by the subsequent demonstration that no offence had in fact been committed. Lord Bridge spoke of the “futility” of giving a power to arrest if its “legality” depended “on whether the person arrested turns out later to have been in fact committing an offence or not”. Similarly, in relation to any “arrestable offence”, the powers of summary arrest granted to police officers by section 24 of the Police & Criminal Evidence Act 1984 may be exercised by a constable with reasonable grounds for suspecting that an arrestable offence has been committed who may arrest anyone “whom he has reasonable grounds of suspecting to be guilty” (see also the general arrest conditions under section 25 of the 1984 Act). Although there was no detailed analysis in argument of the complicated provisions relating to arrest, it is plain that the police constable is not liable to pay damages for false imprisonment on the basis of unlawful arrest merely because in the end the arrest does not result in a conviction. In essence, a wholly innocent man who has been arrested will not necessarily succeed in a claim for damages against the police constable who mistakenly arrested him. The constable may have a lawful excuse for having done so.In my judgment Percy v Hall falls within this principle. On the basis of the provisions of section 17(2) of the Military Lands Act 1892 , as amended by the Criminal Justice Act 1982, it was decided that"......... Even if these bye laws are properly to be regarded as void for uncertainty ...... that would not serve to deprive the constables here of a defence of lawful justification wherever they can show they were acting in the reasonable belief that the plaintiffs were committing a bye law offence." (p.948)Therefore if Michelle Evans had escaped from custody on 10th October 1996 any officers arresting her would have had reasonable grounds for believing that she was unlawfully at large. There would have been no successful claim against them. They would have been able to support the “legality” of the arrest.The permissible scope for error by authorities responsible for detaining prisoners in custody under section 12(1) of the Prison Act 1952 is much narrower than it is for officers affecting an arrest. The order of the court justifies the detention. Nevertheless the prisoner is entitled to be released immediately the sentence has been completed. The method of calculating the date of release depends on statutory provisions which must be applied correctly, that is, correctly in law. For the prison authorities, or governor of any individual prison, to escape liability for any extended period of detention on the basis that they were acting honestly, or on reasonable grounds analogous to those which apply to arresting police officers, a significant extension of the law, reducing the protection currently provided by the tort of false imprisonment, would be required. That step cannot be taken in this court.Like my Lord, the Master of the Rolls, I should allow this appeal on liability.I agree with his judgment on the issue of damages to which there is nothing I can usefully add.

Order

Appeal allowed on liability with costs order nisi. No order as to costs in the court below. Leave to appeal to House of Lords refused. Legal Aid taxation. (Does not form part of approved judgment)

Cited in 1 later judgment