Derby City Council v UYR, R (on the application of) [2025] EWCA Civ 1648

[2025] EWCA Civ 1648Case No CA-2025-002094
IN THE COURT OF APPEAL (CIVIL DIVISION)
[2025] EWHC 2081 (Admin)
ON APPEAL FROM THE HIGH COURT OF JUSTICE
KING’S BENCH DIVISION
Karen Ridge, sitting as a deputy judge of the High Court
Venue Royal Courts of Justice, Strand, London, WC2A 2LLDate 17/12/2025
Before
LORD JUSTICE MOYLANLORD JUSTICE ZACAROLILADY JUSTICE YIP
Between
Derby City CouncilAppellant
Michael Paget (instructed by Derby City Council Legal Services) for AppellantDavid C. Gardner and Susana Ferrin (instructed by Luke & Bridger Law) for RespondentFrancis Hoar (instructed by Manchester City Council Legal Services) for Second Interested PartyThe First Interested Party was not present or representedHearing Hearing date: 27 November 2025
Approved JudgmentThis judgment was handed down remotely at 10.30am on 17 December 2025 by circulation to the parties or their representatives by e-mail and by release to the National Archives..............................
[1]This is an appeal against the order of Karen Ridge sitting as a deputy judge of the High Court, granting interim relief against Derby City Council (“Derby CC”) in the context of a claim for judicial review against Derby CC of their decision, following a brief age assessment, that the claimant is an adult.[2]The appeal raises two short but important issues in the context of claims for interim relief in age assessment cases. First, whether it is a threshold, or gateway, requirement that there is a strong prima facie case on the merits of the underlying judicial review claim. Second, what bearing it has, if any, on the exercise of the balance of convenience in a claim for interim relief against local authority A, that the claimant is already being accommodated as a child by local authority B.

The facts

[3]The claimant, whose country of origin is Ethiopia, arrived in the UK on 17 March 2025. His witness statement recounts the murder of his father and the imprisonment of him and his brother in Ethiopia. In about early 2024 he escaped detention and, with his mother and brother travelled to Libya, where they stayed in a warehouse for six months. They then travelled by boat to Italy, and on to Calais, where the claimant was separated from his family and came to England in the back of a lorry. He told the police on arrival that he was 15 and that his date of birth was 6 October 2009.[4]The claimant was taken to Yarl’s Wood immigration removal centre in Bedfordshire. He was subjected to a brief assessment as to his age by social workers from Bedford Borough Council (“Bedford BC”) on 18 March 2025. Their conclusion was that he was clearly an adult and, as such, there was no requirement to undertake a full “Merton-compliant” age assessment. He was dispersed into adult accommodation and, four days later, moved to Derby.[5]The claimant approached Derby CC claiming to be a child. Derby CC contacted Bedford BC, who provided them with the brief age assessment they had carried out. Derby CC nevertheless proceeded to carry out their own brief age assessment on 28 March 2025. The conclusion of the social workers who carried out the assessment was the same as that reached by Bedford BC: they did not accept his claimed age/date of birth and believed that he was clearly an adult, so that he needed to be supported by the Home Office.[6]On 23 April 2025, the claimant was moved by the Home Office to adult accommodation in the Manchester area.[7]On 2 May 2025, the claimant issued this claim seeking judicial review of Derby CC’s decision, and an application for interim relief.[8]On about 6 May 2025, the claimant collapsed and was admitted to the A&E department of a hospital in Manchester. The staff nurse on duty was of the view that he looked very young and made a safeguarding referral to Manchester City Council (“Manchester CC”). He was then admitted to a children’s ward.[9]Following a visit by emergency duty social workers, Manchester CC decided to accommodate the claimant as a child under s.20 of the Children Act 1989 (the “1989 Act”). They were not aware of the earlier age assessments and did not carry out their own age assessment. Since about 6 May 2025, the claimant has been accommodated in foster care arranged by Manchester CC, apart from a further spell in hospital sometime in the summer of 2025 where he was treated for tuberculosis.[10]The claimant’s application for interim relief came on for hearing on 14 May 2025.[11]By this time, Manchester CC had been made aware of Derby CC’s age assessment, and of the claimant’s challenge to that decision. Manchester CC sought to reach agreement with Derby CC as to what should be done concerning any assessment and future care of the claimant. In an email sent to the Court in Manchester on 14 May 2025, shortly before the hearing of the application for interim relief, Manchester CC’s position was stated to be that:
“the Claimant is currently being accommodated by them but in circumstances such as these the ADCS Joint Working Guidance 2023 together with the ADCS Age Assessment Guidance 2015 state that the Claimant should be referred to the local authority which conducted the previous age assessment … this has been done but agreement has not yet been reached.”

The deputy judge’s judgment

[12]The deputy judge granted the claimant’s application for interim relief. In a succinct and well-reasoned reserved judgment, she applied (from §17 of the judgment onwards) the three-fold test derived from American Cyanamid v Ethicon [1975] AC 396 (“American Cyanamid”):(1) is there a serious issue to be tried?(2) would damages be an adequate remedy to either party?(3) where does the balance of convenience lie?[13]As to the first part of the test, she concluded that, notwithstanding the conclusions reached by Bedford BC and Derby CC, there was a serious issue to be tried, in light (in particular) of the conclusions reached by medical staff at the hospital in Manchester, in making a safeguarding referral, and by the social workers from Manchester CC, in deciding that powers should be exercised under the 1989 Act.[14]As to the second part of the test, the deputy judge noted, at §23, that there is little doubt in the sphere of public administrative law that either party would be harmed by the wrongful grant, or refusal, of interim relief in a way that could not be adequately compensated by damages.[15]As to the third part of the test, the judge identified (at §24) the need to balance, on the one hand, the harm that is done to a person wrongly treated as an adult against both the burden to a local authority in having to provide accommodation to a person who turns out to be an adult and the potential for harm if an adult is housed with vulnerable children. She took particular account (at §25) of the claimant’s deteriorating mental health, the decision by healthcare professionals to treat him as a child and raise safeguarding concerns, and the fact that the status quo was that he was accommodated as a child. She concluded (at §26) that the risk to the claimant’s well-being was a significant factor that weighed in the balance, and that he should therefore be treated as a child pending the outcome of the dispute about his age.[16]At §27 to §30, the deputy judge addressed the argument advanced on behalf of Derby CC that it was unnecessary to grant interim relief because the claimant’s accommodation in foster care was already secured. She rejected that argument, essentially because there was no guarantee that Manchester CC would continue to accommodate the claimant as a child (see §30) and because, if the age assessment carried out by Derby CC was wrong, it was Derby CC that would have the responsibility for safeguarding the needs of the claimant under s.20 of the 1989 Act from the date of the impugned decision (which pre-dated his being accommodated by Manchester CC). That, she concluded, was consistent with the decision of Bean J (as he then was) in R(HA) v London Borough of Hillingdon [2012] EWHC 291 (Admin), and with the Home Office’s Joint Working Guidance on Age Assessment.[17]The deputy

judge ordered interim relief in the following terms:

“[Derby CC] shall treat the Claimant as a putative child aged 15 pending the final conclusion of these proceedings or until further order and shall, within no more than 14 days from the date of this order, secure that the Claimant is provided with accommodation, care and support pursuant to section 20 of the Children Act 1989.”

The grounds of appeal

[18]Derby CC sought permission to appeal on two grounds:(1) The deputy judge erred in principle in failing to find that the claimant had a “strong prima facie case”, this being a threshold requirement for the grant of interim relief; and(2) There was an error in principle in finding that the balance of convenience was satisfied when: (a) The claimant was already being accommodated as a child with a foster family and this was not taken into account when considering prejudice; there was no basis to find that Manchester CC was just providing foster care on an interim basis; (b) The court concluded that Manchester CC could rely on the Joint Working Guidance; (c) Manchester CC had accepted that the claimant was a child and had treated him as a child prior to any knowledge that he disputed Derby CC’s age assessment; and (d) R(HA) v Hillingdon LBC does not deal with the situation where the second authority has, completely independently, accepted a person as a child.[19]The deputy judge granted permission to appeal on the second ground, commenting that this was a novel scenario upon which the Court of Appeal may wish to provide guidance, but refused permission on the first ground. We were told (though this is not recorded in the deputy judge’s order) that in relation to the first ground of appeal she commented that, reading paragraphs 21 and 22 of her judgment together, the claimant had in fact established a strong prima facie case.[20]The deputy judge stayed the order for interim relief until 5 September 2025, in view of the fact that the claimant continued to be accommodated as a child by Manchester CC. On 2 September 2025, Phillips LJ granted permission to appeal on ground 1, and extended the stay on the order for interim relief until after determination of the appeal, provided that the claimant remained in the Manchester area and continued to be regarded as a child by Manchester CC.[21]By a respondent’s notice the claimant contends that the deputy judge’s decision should be upheld on three additional grounds:(1) there is no threshold requirement for a “strong prima facie” case;(2) if there is, the deputy judge found that it was satisfied; and(3) in any event, there was on the facts a strong prima facie case.[22]I note at the outset that counsel for Derby CC, Mr Paget, had not put the case before the deputy judge on the basis that there was a requirement, let alone a threshold requirement, for a strong prima facie case. His skeleton argument for the hearing below relied solely on the three-stage American Cyanamid test. It was not until the application for permission to appeal that the suggestion of a threshold test of strong prima facie case was raised.[23]Manchester CC had been named (along with Bedford BC) as an interested party in the judicial review claim but was not joined as a defendant. No relief was sought against it, and it did not seek any relief against Derby CC. It has filed a respondent’s notice in the appeal, seeking to uphold the deputy judge’s decision on the grounds that interim relief was properly awarded against Derby CC, because it had conducted an age assessment and therefore accepted its responsibility to support the claimant if he was a child.

The legislative background

[24]Every local authority is under a general duty to safeguard and promote the welfare of children within their area who are in need: s.17(1)(a) of the 1989 Act.[25]A child is someone under the age of 18: s.105(1) of the 1989 Act. A child is “in need” if (see s.17(10) of the 1989 Act):(a) he is unlikely to achieve or maintain, or to have the opportunity of achieving or maintaining, a reasonable standard of health or development without the provision for him of services by a local authority under this Part;(b) his health or development is likely to be significantly impaired, or further impaired, without the provision for him of such services; or(c) he is disabled”.[26]By s.20(1) of the 1989 Act:
“Every local authority shall provide accommodation for any child in need within their area who appears to them to require accommodation as a result of— (a) there being no person who has parental responsibility for him; (b) his being lost or having been abandoned; or (c) the person who has been caring for him being prevented (whether or not permanently, and for whatever reason) from providing him with suitable accommodation or care.” (a) there being no person who has parental responsibility for him; (b) his being lost or having been abandoned; or (c) the person who has been caring for him being prevented (whether or not permanently, and for whatever reason) from providing him with suitable accommodation or care.”
[27]There is no dispute that if the claimant is a child then, as an unaccompanied migrant without family or other help in this country, he is “in need” and requires accommodation.[28]In s.27 of the 1989 Act, provision is made for co-operation between local authorities:
“(1) Where it appears to a local authority that any authority mentioned in subsection (3) could, by taking any specified action, help in the exercise of any of their functions under this Part, they may request the help of that other authority specifying the action in question. (2) An authority whose help is so requested shall comply with the request if it is compatible with their own statutory or other duties and obligations and does not unduly prejudice the discharge of any of their functions.”

Guidance

[29]We were shown guidance promulgated jointly by the Home Office and the Association of Directors of Children’s Services in 2023 entitled Age Assessment Joint Working Guidance (“the Joint Working Guidance”). Among other things, the Joint Working Guidance suggests what should be done where a young person is age assessed by more than one local authority, and with different outcomes (or where there are conflicting age assessments as between a local authority and the National Age Assessment Board, which carries out age assessments on behalf of the Home Office).[30]Section 6.2 deals with conflicting assessments between local authorities. The core guidance is that local authorities “must work together, and with other agencies, and be sure they prioritise safeguarding the individual and adhere to the Children Act 1989 and the Children Act 2004”. If the Home Office becomes aware of conflicting age assessments of different local authorities, it must notify the local authorities concerned “for them to agree which LA should take responsibility”.[31]In cases where new information relevant to the assessment comes to light after an age assessment has been carried out by local authority A, and the individual has moved location to local authority B, “this should be referred to [local authority A] and agreement reached between the LAs, depending on the circumstances, as to which LA will reassess the age of the individual, taking full account of all sources of information.”[32]The Joint Working Guidance notes that a young person may seek judicial review of an age assessment, and provides:
“then the courts – in exercising their judicial review function – may make a final finding on age which is binding on all agencies (known as a declaration in rem), including the Home Office and the LA (R(on the application of S) v Croydon LBC [2011] EWHC 2091 (Admin).”

Ground 1

[33]For the reasons which follow, I reject Derby CC’s contention that there is a threshold test of strong prima facie case upon an application for interim relief in an age assessment judicial review claim. The test, so far as the merits of the claim is concerned, is that there is a serious issue to be tried or, as it is sometimes expressed, a real prospect of success. If that test is satisfied, then the court must go on to consider where the balance of convenience lies.[34]The principles governing the grant of interim relief in judicial review proceedings, generally, were set out by Cranston J in R (on the application of Medical Justice) v Secretary of State for the Home Department [2010] EWHC 1425 (Admin), at §6 to §7:
“The principles governing the grant of interim relief in judicial review proceedings are those contained in the well known decision of [American Cyanamid], but modified as appropriate to public law cases. First, the claimant must demonstrate that there is a real prospect of succeeding at trial. This seems to equate with something more than a fanciful prospect of success. In Smith v Inner London Education Authority [1978] 1 All AER 411, the claimants had obtained an interim injunction in relation to the closure of a grammar school. On appeal, Lord Denning acknowledged that American Cyanamid could not automatically fit with public law cases, but held that, without going into details, a public authority should not be restrained from exercising its statutory power or doing its duty to the public unless the claimant could show a real prospect of succeeding at the trial (P418, e to f). Browne LJ said this (at 419, b to c): “The first question is whether the plaintiffs have satisfied the first requirement laid down by the House of Lords in [American Cyanamid]: is their action not frivolous or vexatious? Is there a serious question to be tried? Is there a real prospect that they will succeed in their claim for a permanent injunction at the trial? The first two questions were clearly intended to state the same test, because they are joined by the phrase 'in other words', and the third cannot, I think, have been meant to state any different one.” 7. In Sierbein v Westminster City Council [1987] 86 LGR 43, the Court of Appeal agreed with the approach in Smith v Inner London Education Authority, although underlined the importance of the public interest in an application for an interim injunction against a public authority: see Dillon LJ at 440.” “The first question is whether the plaintiffs have satisfied the first requirement laid down by the House of Lords in [American Cyanamid]: is their action not frivolous or vexatious? Is there a serious question to be tried? Is there a real prospect that they will succeed in their claim for a permanent injunction at the trial? The first two questions were clearly intended to state the same test, because they are joined by the phrase 'in other words', and the third cannot, I think, have been meant to state any different one.”
[35]Mr Paget, who appeared for Derby CC, submitted that a different test applies in applications for mandatory orders by way of interim relief. This was based on three cases.[36]The first is De Falco v Crawley BC [1980] QB 460 (“De Falco”). The claimants, two Italian nationals, applied to Crawley Borough Council as homeless persons with a priority need under s.2(1) of the Housing (Homeless Persons) Act 1977. The council determined that they had made themselves intentionally homeless. The claimants sought judicial review of that decision and applied for an interim injunction requiring the council to provide accommodation. Chapman J refused to grant an injunction, and his decision was upheld by the Court of Appeal. Lord Denning MR, at p.478C said:
“This is not the same sort of case as [American Cyanamid] because the plaintiffs here cannot give any worthwhile undertaking in damages. No injunction should be granted against the council unless the plaintiffs make out a strong prima facie case that the council’s finding of “intentional homelessness” was invalid.”
[37]Bridge LJ gave fuller reasons for reaching the same conclusion, at p.481B-G. He first noted that there was little assistance to be derived from authority, and the American Cyanamid principles “have no relevance to the case we are considering”, because of the unusual features of a disputed application to be provided with accommodation by a local authority. He then said that the appropriate principles were to be derived from a consideration of the likely consequences of granting or withholding relief, balancing the harm to the applicant of being rendered homeless (which could not be compensated in damages) against the financial burden to the local authority of providing accommodation (which it stood no chance of recovering from the applicant). He continued:
“What is perhaps more important, a mandatory injunction to provide accommodation for a particular applicant who ought not to enjoy priority may operate to the detriment of others on the local authority's housing list by interfering with the local authority's own system of priorities for the fair distribution of limited housing resources. In the light of these considerations, I think the court inevitably must make the best assessment it can, on an interim application for a mandatory injunction, of the strength of the applicant's claim to impugn the local authority's decision adverse to him and should only grant the relief sought if a strong prima facie case is made out.”
[38]I note that neither Lord Denning nor Bridge LJ referred in terms to a threshold or gateway condition that there must be a strong prima facie case. Bridge LJ’s analysis appears to tie the need for a strong prima facie case to the balancing exercise to be carried out. The only reason offered by Lord Denning was that damages are not an adequate remedy in judicial review cases, but that is something that cuts both ways and it is difficult to see why it would justify a higher merits test as a threshold to considering where the balance of convenience lies. The suggestion by Bridge LJ that the American Cyanamid principles play no part at all has not been adopted in more recent authority, as I explain below.[39]The second case relied on by Mr Paget is Francis v Kensington and Chelsea Royal London BC [2003] 1 WLR 2248. An interim injunction was sought to require a housing authority to provide accommodation pending determination of an appeal against the housing authority’s refusal to provide temporary accommodation under s.204A(2) of the Housing Act 1996. The power of intervention on such an appeal was the same as in a substantive claim for judicial review. At §16, Simon Brown LJ (with whom the only other member of the court, Rix LJ, agreed) held that the approach to adopt in considering whether to grant an interim mandatory injunction was that set out by the Court of Appeal in De Falco, such that relief would not be granted unless the applicant could show a strong prima facie case. This was, he said, “in line with the settled law that a higher standard is required for a mandatory rather than a prohibitionary injunction: see Morris v Redland Bricks Ltd [1970] AC 652.”[40]The suggestion that a different approach is warranted, as between mandatory and prohibitory injunctions, must now be seen in the light of the comments of Lord Hoffmann in National Commercial Bank Jamaica Limited v Olint Corporation Limited [2009] UKPC 16; [2009] 1 WLR 1405. At §19 he said there was no reason to suppose that Lord Diplock in American Cyanamid had intended to limit the principles to prohibitory as opposed to mandatory injunctions: “In both cases, the underlying principle is the same, namely, that the court should take whichever course seems likely to cause the least irremediable prejudice to one party or the other”, citing R v Secretary of State for Transport, ex parte Factortame [1990] 1 AC 603. He continued: “What is true is that the features which ordinarily justify describing an injunction as mandatory are often more likely to cause irremediable prejudice than in cases in which a defendant is merely prevented from taking or continuing with some course of action: see Films Rover International Ltd v Cannon Film Sales Ltd [1987] 1 WLR 670, 680. But this is no more than a generalisation. What is required in each case is to examine what on the particular facts of the case the consequences of granting or withholding of the injunction is likely to be. If it appears that the injunction is likely to cause irremediable prejudice to the defendant, a court may be reluctant to grant it unless satisfied that the chances that it will turn out to have been wrongly granted are low; that is to say, that the court will feel, as Megarry J said in Shepherd Homes Ltd v Sandham [1971] Ch 340, 351, “a high degree of assurance that at the trial it will appear that the injunction was rightly granted”.[41]It was those reasons that led Lord Hoffmann (at §20) to refer to the arguments over whether an injunction should be classified as prohibitive or mandatory as “barren”.[42]The third case is British Standards Institution v R (on the application of RRR Manufacturing Pty Ltd) [2024] EWCA Civ 530 (“RRR”). RRR marketed a portable defibrillator. Under the relevant regulatory regime, RRR required a certificate from the British Standards Institute (“BSI”). It had such a certificate, but BSI decided to suspend it. RRR applied for judicial review and sought interim relief. Lang J granted an order restraining BSI from withdrawing authorisation and requiring it to extend certification (when it expired on 26 May 2024) until the determination of the application for judicial review. That was overturned by this Court.[43]The appellant in RRR contended, in reliance on De Falco, that it was necessary, in order to obtain a grant of mandatory interim relief, to demonstrate a strong prima facie case, as a threshold test and not merely as part of the assessment of the balance of convenience (see §55 of the judgment of Elisabeth Laing LJ). The respondent submitted that De Falco had been doubted in some first instance decisions and referred to Lord Hoffmann’s comment in National Commercial Bank Jamaica Limited v Olint Corporation Limited [2009] UKPC 16; [2009] 1 WLR 1405, that in considering the balance of convenience, the attempt to distinguish between mandatory and prohibitive injunctions was “barren” (see §65).[44]The first ground of appeal was as to the nature of the court’s jurisdiction to grant interim relief on an application for judicial review. Elisabeth Laing LJ (with whom Nugee LJ and Snowden LJ agreed) said (at §76) that the court’s jurisdiction is derived from its powers in relation to prerogative writs and is now found in s.31 of the Senior Courts Act 1981. The court applied, however, by analogy, the principles in American Cyanamid.[45]The second ground of appeal included the discrete question whether De Falco had been overruled in later cases. As to that, Elisabeth Laing LJ said, at §87:
“Mr Heppinstall suggested that the approach in De Falco is no longer good law. He did not identify any case in which it had been overruled, but relied on some obiter observations in one case in this court, first instance decisions in the Administrative Court and two decisions in private law cases. One of the first instance decisions, which concerned a dispute about age assessment, is not relevant, as such disputes are a rare example of disputes in which the Administrative Court (or the Upper Tribunal) makes a factual decision on an application for judicial review, and, as a result, the test for granting permission to apply for judicial review in such cases is different from the test in most public law cases. I do not accept his submission that the cases on which he relied show that De Falco is no longer good law.”
[46]The fact that, in judicial review proceedings against an age assessment, the age of the young person concerned is an objective fact subject to ultimate determination by a court, was established by the Supreme Court in R(A) v Croydon London BC [2008] UKSC 8; [2009] 1 WLR 2557. That is in contrast to the court being required to review the local authority’s decision on conventional public law principles, where considerable deference is afforded to the primary decision maker’s decision.[47]Nugee LJ, at §112 of RRR agreed that De Falco requires that a strong prima facie case be shown for the grant of a mandatory order against a public authority, and that this is a threshold requirement, not simply a matter for the balance of convenience.[48]Mr Gardner, who appeared with Ms Ferrin for the respondent, did not expressly challenge the proposition that it is generally a requirement in an application for interim mandatory relief in the context of a claim for judicial review to establish as a threshold requirement that there is a strong prima facie case, although he (as he put it) “raised an eyebrow” at it. In support of the raised eyebrow, he referred to the judgment of this Court in R(X) v Office for Standards in Education [2020] EWCA Civ 594. At §63 to §64, Lindblom LJ cited passages from Lord Goff in Factortame (above), including the following at p.674A-D:
“I myself am of the opinion that in these cases, as in others, the discretion conferred upon the court cannot be fettered by a rule; I respectfully doubt whether there is any rule that, in cases such as these, a party challenging the validity of a law must – to resist an application for an interim injunction against him, or to obtain an interim injunction restraining the enforcement of the law—show a strong prima facie case that the law is invalid. It is impossible to foresee what cases may yet come before the courts; I cannot dismiss from my mind the possibility (no doubt remote) that such a party may suffer such serious and irreparable harm in the event of the law being enforced against him that it may be just or convenient to restrain its enforcement by an interim injunction even though so heavy a burden has not been discharged by him. In the end, the matter is one for the discretion of the court, taking into account all the circumstances of the case. Even so, the court should not restrain a public authority by interim injunction from enforcing an apparently authentic law unless it is satisfied, having regard to all the circumstances, that the challenge to the validity of the law is, prima facie, so firmly based as to justify so exceptional a course being taken.”
[49]Lindblom LJ observed, at §66, that there was support at first instance for the proposition that in a public law claim the court will generally be reluctant to grant interim relief in the absence of a strong prima facie case, but that was:
“not to say that the relevant case law at first instance supports the concept of a ‘strong prima facie case’ being deployed as a ‘threshold’ or ‘gateway’ test in such cases, but rather that the underlying strength of the substantive challenge is likely to be a significant factor in the balance of considerations weighing for or against the granting of an injunction.”
[50]Mr Gardner submitted, however, that irrespective of the position more generally, there is no threshold requirement of strong prima facie case on an application for interim relief in a claim for judicial review in an age assessment case.[51]He pointed to a number of first instance cases where the Administrative Court has declined to follow De Falco in an age assessment context. He referred us to a decision of Michael Fordham QC (as he then was) in R(BG) v Oxfordshire County Council [2014] EWHC 3187 (Admin). It was common ground in that case that it would not be appropriate or necessary to apply a “degree of arguability” approach. Of more relevance is the decision of Nicol J in R(AS) v Liverpool City Council [2021] EWHC 3531 (Admin). At §10 to §12, Nicol J recited the argument of Mr Paget (who appeared for the local authority in that case) that normally the court would consider whether there was a strong prima facie case before displacing the decision of a local authority. He noted the contrary argument that the test was context dependent and that, in that case (as here) the context was that the court would have to decide for itself if the claimant was a child. He recited Mr Paget’s argument that a higher prospect of success was required where a mandatory injunction was sought and noted the contrary argument that the distinction between prohibitory and mandatory injunctions had been disapproved by Lord Hoffmann in the National Commercial Bank Jamaica case. At §13, he concluded:
“The resolution of this issue is, in my judgment, that there is no hard and fast rule that a claimant like AS must show a strong prima facie case, even though the relief sought might be characterised as a mandatory injunction, but that characterisation is one factor which can properly be taken into account in assessing the balance of convenience. The strength of the claimant’s claim (so far as it can be judged) is also a factor to be taken into account in the balance of convenience.”
[52]As to the other cases cited by Mr Gardner, I need merely note that on a number of occasions the Administrative Court has followed Nicol J’s approach and applied the American Cyanamid principles, adapted as in the Medical Justice case to the public law context. Fordham J, in R(KKA) v Cheshire East Council [2024] EWHC 575 (Admin) referred to most of these cases, describing them as “working illustrations”, and concluded, at §16:
“There is no higher threshold requiring a “strong prima facie case”, whether by reference to (a) the public law context (b) interim relief as being “mandatory” (c) the extent to which interim relief will resolve the substance of the case or (d) otherwise. Instead, the Court’s provisional assessment of the claim’s strength or weakness can be a factor which informs the balance of justice.”
[53]Mr Paget characterised all of these first instance decisions as an unjustified departure from binding case law.[54]Mr Gardner, however, correctly observed that no case has held that there is such a threshold test in the context of age assessment and, moreover, in the passage quoted above from Elisabeth Laing LJ’s judgment in RRR, age assessment cases were expressly distinguished.[55]In my judgment, even if there is a higher threshold in judicial review cases generally (which it is unnecessary to decide on this appeal), having regard to the reasons why such a test is said to be justified, there are sound reasons in principle why it does not apply in age assessment cases.[56]For the reasons already given, two of the justifications for needing a strong case offered in De Falco and Francis (the absence of damages as an adequate remedy and the difference between mandatory and prohibitory injunctions) carry little if any weight. To the extent that the remaining justifications might support a higher threshold test in judicial review claims generally, they do not apply in the context of a challenge to an age assessment.[57]First, as observed by Elisabeth Laing LJ in RRR, there is an important difference, so far as the court’s role is concerned, between a judicial review claim in an age assessment case and other judicial review claims. In most cases where judicial review is sought of a public authority’s decision, the court will give considerable deference to that decision. The public authority remains the decision-maker and the scope for intervention by the court is limited to identifying irrationality, or errors of law or procedure. To the extent that the heightened bar for intervention in such cases is said to warrant a higher merits threshold for the grant of interim relief, that has no application in an age assessment case, where it is for the court to reach its own decision as to the age of the claimant.[58]Second, the importance of affording deference to the public authority’s decision where – as in De Falco itself (per Bridge LJ) – a mandatory injunction to provide accommodation for a particular person may operate to the detriment of others on the housing authority’s list has no application in an age assessment case. While the consequences of a conclusion that the person is a child can impose a significant financial burden on the relevant local authority, there is no direct impact on other children within the local authority’s jurisdiction because a local authority is obliged to provide accommodation for a child in need, irrespective of how many other children in need there are within its jurisdiction.[59]Accordingly, I reject the submission that there is a threshold requirement, upon an application for interim relief in a claim for judicial review of an age assessment, that there must be a strong prima facie claim. The threshold question is that derived from the first stage of the American Cyanamid test: is there a serious issue to be tried?[60]I mention for completeness that one issue debated between the parties was the relevance of(1) Article 3 of the United Nations Convention on the Rights of the Child (which mandates that in all actions concerning children, the interests of the child shall be a primary consideration) and(2) the conclusion of Lavender J in R(S) v Croydon London Borough Council [2017] EWHC 2656 (Admin) that a putative child awaiting an assessment was to be treated as a child unless there were cogent reasons for not doing so, in light of the statutory guidance. Whether or not, and to what extent, these matters are relevant to weigh in the balance at the third stage of the American Cyanamid test, they do not in my view have any bearing on the question whether there is a heightened merits threshold at the first stage of the test.[61]My conclusion on ground 1, and the first aspect of the respondent’s notice, makes it unnecessary to consider what the epithet “strong” adds to the need for a prima facie case, or how that differs from a serious issue to be tried, in the context of the binary question of fact raised by an age assessment case. Had it been necessary to do so, I would have concluded that the matters identified in §21 and §22 of the judge’s judgment – particularly the fact that a medical professional who observed the claimant, and two social workers from Manchester CC, accepted that the claimant was a child without the need to carry out any assessment – justified a conclusion that there is in any event a strong prima facie case.

Ground 2

[62]In considering Ground 2 it is important first to note that Derby CC do not object to the deputy judge’s conclusion that – leaving aside the fact that the claimant is already being accommodated as a child by Manchester CC – this is a case where the balance of convenience comes down in favour of the claimant being accommodated (somewhere, at least) as a child pending the outcome of the judicial review proceedings.[63]Derby CC’s objection is instead that the deputy judge made an error of principle in finding that the balance of convenience came down in favour of ordering Derby CC to secure the provision of accommodation, care and support for the claimant, when the claimant was already being treated by Manchester CC as a child and being provided by them with accommodation, care and support accordingly.[64]Specifically, Mr Paget submitted that the judge was wrong:(1) to base her decision on the fact that Manchester CC were “looking to Derby CC to potentially assume the care of the Claimant or come to some agreement having regard to the advice within the Joint Working Advice”;(2) to rely on the Joint Working Guidance at all; and(3) to rely on the fact that “there is no guarantee” that Manchester CC will continue to accommodate the Claimant as a child now that they were aware of the dispute as to his age.[65]The principal error, he submitted, was that this ignored the fact that, Manchester CC having assumed responsibility towards the claimant as a child, it could not simply choose to stop doing so. At the very least, it would first have to decide to undertake its own age assessment. Only if it were to conclude that the claimant was an adult would there be any possibility of it ceasing to provide accommodation, care and support to the claimant and, even then, its decision would itself be susceptible to judicial review within which interim relief could be sought if necessary. In light of those matters, there was no risk to the claimant if interim relief were refused as against Derby CC, and thus no basis for the balance of convenience, as between the claimant and Derby CC, falling in the claimant’s favour.[66]Mr Gardner, for the respondent (who was the claimant before the deputy High Court judge), submitted that the judge was entitled, on the information before her at the hearing, to conclude that the current arrangement whereby the claimant was accommodated by Manchester CC was precarious because Manchester CC was merely exercising, on an interim basis, a safeguarding duty towards a putative child.[67]Most of the running on the respondents’ side on this part of the case was done by Mr Hoar, who appeared for Manchester CC. I did not understand him to dispute that Manchester CC was not currently in a position unilaterally to cease treating the claimant as a child. He accepted that, at the very least, Manchester CC would first need to conduct its own age assessment. This was an implicit, if not explicit, acceptance that Manchester CC is currently subject to a s.20 obligation in respect of the claimant.[68]Mr Hoar frankly accepted that it would be “invidious” to require a young person who was settled in foster care to leave that foster care. His submissions were instead, therefore, directed towards a solution whereby the claimant remained pending determination of the judicial review proceedings in the foster care in which he was already accommodated, but it was paid for by Derby CC. There is precedent, he said, for requiring local authority A (which is under a s.20 obligation in respect of a child) to pay for that child’s accommodation provided by (and within the geographical area) of local authority B.[69]His first submission was that the deputy judge’s order implicitly recognised this, because it merely required Derby CC to “secure” that the claimant is provided with accommodation, care and support and that this could be achieved by Manchester CC continuing to provide accommodation, “secured for” by being reimbursed by Derby CC.[70]I do not think that was either the intention behind, or the meaning of, the wording of the deputy judge’s order. Manchester CC were not represented at the hearing before the judge, and there was no argument before her as to the respective financial responsibilities as between Derby CC and Manchester CC.[71]Mr Hoar proposed, in the alternative, a solution whereby this Court varied the terms of the judge’s order to provide for the same result.[72]For the reasons I develop below, I have concluded that the judge was wrong to conclude that the claimant’s current accommodation position was precarious, and for that reason erred in concluding that the balance of convenience came down in favour of ordering interim relief against Derby CC. I have also concluded that Mr Hoar’s proposed solution is not the appropriate course to take on this appeal.[73]At the heart of Mr Hoar’s submissions is the proposition that Derby CC, having carried out an age assessment, retained responsibility for the claimant if it was established in the judicial review proceedings that the claimant is a child, and it is therefore Derby CC at which any order for interim relief should be directed.[74]Mr Hoar relied principally on two cases: Liverpool City Council v Hillingdon London Borough Council [2009] EWCA Civ 43; [2009] PTSR 1067 (“Liverpool v Hillingdon”); and R(HA) v London Borough of Hillingdon [2012] EWHC 291 (Admin) (“HA v Hillingdon”).[75]Liverpool v Hillingdon was a dispute between two local authorities, which arose in the following circumstances. K, a Pakistani national, arrived in the UK with false papers and applied for asylum in Liverpool, claiming he was 15 years old. A Liverpool council officer assessed his age as 18 and referred him to the National Asylum Support Service. K was detained as an adult successively in Oxford and Hillingdon, where his asylum request was rejected. On K’s appeal, an immigration judge accepted a doctor’s assessment that he was 15 and he was transferred to Hillingdon social services. K wished to return to Liverpool. Without making any further investigation into K’s age, Hillingdon arranged for a social worker to accompany K to Liverpool social services. He was thereafter accommodated in Liverpool but as an adult. Liverpool issued judicial review proceedings claiming that Hillingdon had a statutory duty to conduct an age assessment and to provide K with accommodation under s.20 of the 1989 Act pending that assessment, and that it acted unlawfully in removing K to Liverpool without having conducted an age assessment of him.[76]It was common ground in the case that, by reason of the conflict between the original age assessment made by Liverpool and the decision of the immigration judge to accept the expert opinion of a doctor giving evidence in the immigration appeal that K was child, a reassessment of K’s age was necessary. It was also common ground that K needed to be accommodated at least during the assessment process. The dispute was as to which local authority was responsible for accommodating him.[77]At first instance, the judge held that Hillingdon became responsible for K, as he was discharged within their area, and they had accommodated and interviewed him. He also held, however, that Hillingdon’s responsibility ceased once they had returned K to Liverpool, in accordance with his own wishes.[78]On appeal, it was not in dispute that once K was within the area of Hillingdon, the duty under s.20 of the 1989 Act fell upon Hillingdon. Dyson LJ, with whom Rix LJ and Wilson LJ agreed, held that Hillingdon had wholly failed to comply with that duty. He rejected the argument that Hillingdon had complied with its duty by acting in accordance with K’s wishes.[79]The relevance of the case, so far as this appeal is concerned, is said to lie in the fact that the Court of Appeal held that Hillingdon’s duty did not cease on K being removed from Hillingdon, and a mandatory order was made against Hillingdon requiring it to carry out an age assessment, and to accommodate K while doing so. Mr Hoar relied in particular on a passage at §22:
“Hillingdon could have said that it was discharging the section 20 duty without prejudice to its contention that it had no obligation to do so. But it did not take that course.”
[80]Mr Hoar suggested that reflected Manchester CC’s stance in this case. I do not accept that. Albeit that it did so in ignorance of the earlier age assessments in both Bedford and Derby, Manchester CC accepted responsibility for the claimant as a child without reservation. According to the email sent by Manchester CC to the court on 14 May 2025, its emergency duty social workers who responded to the safeguarding referral from the hospital, “decided to accommodate the Claimant after he was discharged from hospital”. There was no mention of this being without prejudice to whether Manchester CC had any obligation under s.20.[81]In HA v Hillingdon, the claimant (“HA”) was an asylum seeker from Afghanistan who arrived in the UK in March 2011 claiming to be 14. The Hillingdon social workers who completed a core assessment of his needs considered that he appeared to be the age he claimed. Three months later, however, Hillingdon conducted a more detailed age assessment and concluded that HA was over 18. He was placed by the UK Border Agency in hostel accommodation in Birmingham.[82]HA issued proceedings seeking to judicially review the age assessment carried out by Hillingdon. An application for permission and interim relief came before Bean J. He granted permission. On the interim relief application, Hillingdon argued that if anyone was liable to provide accommodation and support to HA, it was Birmingham City Council, in whose area HA had been living since being moved there by the UK Border Agency. Bean J adjourned the hearing to give Birmingham the opportunity to make representations. At the adjourned hearing, he refused the application to join Birmingham as a defendant and granted interim relief against Hillingdon alone.[83]The case advanced by Hillingdon was that as HA was now within the area of Birmingham, any s.20 duty owed by Hillingdon had ended, so it was now for Birmingham to provide accommodation and support. Bean J rejected that argument, holding (at §14):
“in my view Parliament cannot have intended a simple geographical test to be applied. It would mean that an applicant dissatisfied with his age assessment by the original authority (or with the standard of s 20 accommodation and support supplied by them) could simply travel to another authority and demand to be reassessed, or provided with better accommodation. It would also encourage dumping of applicants by one authority on another: in Lady Hale’s phrase, passing them from pillar to post.”
[84]That last sentence was a reference to a passage in the judgment of Lady Hale in R(G) v Southwark London Borough Council [2009] 1 WLR 1299, in which she approved the following as one of six questions for determining the existence of a s.20 duty:
“Is he within the local authority’s area? This again is not contentious. But it may be worth remembering that it was an important innovation in the forerunner provision in the Children Act 1948. Local authorities have to look after the children in their area irrespective of where they are habitually resident. They may then pass a child on to the area where he is ordinarily resident under section 20(2) or recoup the cost of providing for him under section 29(7). But there should be no more passing the child from pillar to post while the authorities argue about where he comes from.”
[85]Liverpool v Hillingdon was cited to Bean J in support of the proposition that a local authority cannot discharge their s.20 duty by relying on their own unlawful act (in that case, if HA was found to be a child, Hillingdon’s refusal of services to HA following their assessment of him as an adult). Bean J accepted that proposition, at least for the purposes of the claim before him. Recognising that he was only concerned with interim relief until the lawfulness of Hillingdon’s age assessment was determined, he concluded, at §22:
“I consider that on facts such as in the present case, in the period between an age assessment and the determination before this court or the Upper Tribunal of a challenge to the correctness of that assessment, it should be the original assessing authority against whom interim relief is granted.”
[86]I accept that the above authorities provide support for the deputy judge’s conclusion (at §29 of her judgment) that if Derby CC turns out to be wrong about the claimant’s age, then it would have had responsibility for safeguarding the needs of the claimant under s.20 of the 1989 Act from 28 March 2025, the date of the impugned decision. Although it was the Home Office that moved the claimant from Derby to Manchester, that would not have occurred had Derby CC concluded that the claimant was a child and, until the judicial review proceedings are determined, it is not known whether Derby CC’s decision was lawful or not.[87]It necessarily follows, that, at least in this interim period, the possibility exists that both Manchester CC and Derby CC owe concurrent duties under s.20 of the 1989 Act. The possibility of concurrent duties being owed was acknowledged by Rix LJ in Liverpool v Hillingdon (at §44). We were not specifically addressed on this point, and in view of Mr Hoar’s acceptance that Manchester CC is under such a duty it is unnecessary to reach a final determination on it. For my part, however, and given the geographical foundation for the duty upon a local authority, I do not see why two or more local authorities may not owe concurrent duties. The passage from the Joint Working Guidance referred to at §‎30 above acknowledges this and recommends that local authorities should try to agree on which of them takes responsibility.[88]This appeal, however, involves a different question: whether an order for interim relief is justified against Derby CC, applying the third stage of the American Cyanamid test, in circumstances where the claimant is already being provided with accommodation, care and support by Manchester CC pursuant to its own s.20 duty.[89]It is important to keep in mind the need both to discourage applicants travelling from one authority to another until they obtain a favourable age assessment and to discourage dumping of applicants by one authority on another. This case, however, raises neither issue.[90]As I have noted above, the judge’s conclusion was premised on her understanding that there was no guarantee that Manchester CC would continue to accommodate the claimant. In my judgment, the premise was mistaken, for two reasons.[91]First, because on the information available to the judge, being the email from Manchester CC shortly before the hearing (see §‎80 above), Manchester CC had “decided to accommodate the Claimant after he was discharged from hospital” without reservation. The same email makes it clear that it was only later that Manchester CC became aware of the previous age assessments and sought to reach agreement with Derby CC as to the future care of the claimant.[92]Second, in agreement with the submissions of Mr Paget recorded at §‎65 above, Manchester CC cannot simply choose to cease to accommodate the claimant, and the prospect of it doing so while the issue over the claimant’s age is before the court and remains unresolved is remote. The fact that Manchester CC is keen to reach some agreement with Derby CC about the future accommodation for the claimant does not imply that the current arrangements are precarious. Mr Hoar’s frank acknowledgement that it would be invidious to move the claimant from his current foster care, together with the fact that he directed his submissions towards a solution that required Derby CC to fund Manchester CC’s provision of accommodation, reinforces that conclusion. Lady Hale’s comment that there should be no more passing a child from pillar to post while the authorities argue about where he comes from (see §‎84 above) also indicates that the right interim solution in this case is that the claimant remains accommodated by Manchester CC.[93]It follows, in my judgment, that in considering the application for interim relief by the claimant against Derby CC, there is no need for any such relief because the claimant is already adequately accommodated by Manchester CC. It is no part of the balancing exercise between the claimant and Derby CC to consider who – as between Derby CC and Manchester CC – should be liable for the cost of the claimant’s interim accommodation. It is not otherwise an issue that fell to be resolved on the application before the deputy judge for interim relief, or falls to be resolved on this appeal, where Manchester CC has not been joined as a defendant and has not itself made any application against Derby CC.

Conclusion

[94]For the above reasons, I would dismiss the appeal on ground 1 but, while acknowledging that the deputy judge reached an unimpeachable conclusion that the claimant ought to be accommodated as a child pending the resolution of the judicial review proceedings, I would allow the appeal on ground 2. That is on the basis that the deputy judge erred in considering that the provision of accommodation by Manchester CC was precarious, and she ought to have held that there was no real risk that the claimant would cease to be accommodated as a child pending resolution of the judicial review proceedings, so that the balance of convenience came down against ordering interim relief against Derby CC.[95]I agree.[96]I also agree.

Cited in 1 later judgment