MRS C WILSON v HEALTH AND SAFETY EXECUTIVE [2008] UKEAT 0050_08_1912

EMPLOYMENT APPEAL TRIBUNAL
BAILII case number: [2008] UKEAT 0050_08_1912Case No Appeal No. UKEAT/0050/08Venue 58 VICTORIA EMBANKMENT, LONDON EC4Y 0DS
Between
MRS C WILSONAPPELLANTHEALTH AND SAFETY EXECUTIVERESPONDENT
Before
Mr Justice EliasDate 19 December 2008
[1]APPEARANCES For the Appellant MS TESS GILL (of Counsel) Instructed by: Prospect New Prospect House 8 Leake Street LONDON SE1 7NN For the Respondent MS JENNIFER EADY (One of Her Majesty's Counsel) and MR ROBERT MORETTO (of Counsel) Instructed by: Treasury Solicitors One Kemble Street LONDON WC2B 4TS SUMMARY EQUAL PAY ACT: Article 141/European law EQUAL PAY ACT: Material factor defence and justification The claimant contended that a system which rewarded pay in part by reference to length of service constituted a breach of the Equal Pay Act 1970 . She accepted that the nature of the job was one where job performance would be likely to improve with experience for the first few years, but submitted that the employer was not justified in applying it over a ten year period. The employment tribunal agreed and considered that five years would have been the appropriate period. However, they held that the effect of the decision of the ECJ in Cadman v HSE [2006] ICR 1623 was that as long as the nature of the job was such that some differential based on length of service could be justified, the tribunal could not thereafter question the particular way in which the criterion was applied. Accordingly, since it was conceded that some link was justified, the appeal failed. The EAT upheld the appeal and held that this was too restrictive a reading of the Cadman decision. Observation on the effect of that decision and how tribunals should approach cases of this kind. THE HONOURABLE MR JUSTICE ELIAS (PRESIDENT) The claimant was employed as a band 3 inspector in the Health & Safety Executive ('HSE'). She presented a claim for equal pay on 1 July 2002. She relied upon three comparators, each of whom was also a band 3 inspector and each of whom had been rated as equivalent in a job evaluation study carried out in 1995. They were paid more than her and in part this was because of their longer service.[2]The precise detail of the incremental scale which caused pay to vary with length of service need not be set out. It was extremely complicated. Mercifully, counsel agreed that it was sufficient for the purposes of this appeal to say that typically it covered a progression of 10 years after which time no further increments were awarded. This was not the only factor that caused the pay of the claimant and the comparators to vary, but the claimant accepted that the other factors, which included loyalty bonus, were justified.[3]There was a hearing before the Tribunal (the first hearing) in early summer 2003 at which it found that the criterion of length of service had a disparate impact on female employees. This was because overall they would tend to have shorter service than males because of career breaks to have children and, in some cases, because of commencing employment at a later date than would otherwise have been the case because of child care responsibilities.[4]The Tribunal went on to consider whether the service-linked pay was objectively justified. It was common ground between the parties that the HSE was justified in having an incremental scale to reflect length of service for a period beyond the initial appointment on the basis that somebody with experience was of more value to the HSE than a relative newcomer. This was in accordance with the following observation in the Megaw inquiry conducted into the Civil Service in 1993:
"Incremental scales reflect the fact that individuals take time to become fully proficient in all the work of their grade and make it possible to recognise increasing experience and provide some incentive for staff to stay at an organisation."
[5]There was, however, disagreement between the parties about to how long that period should be. The claimant herself thought that three years was appropriate. Mr Strawson, a trade union official who gave evidence on her behalf and was himself an HSE officer, considered five was the right level. The actual band adopted by the employers was ten years.[6]It was argued for the employers that ten years was appropriate but that in any event the effect of the decision of the European Court of Justice ('ECJ') in Danfoss (Handels-OG Kontorfunktionaerernes Forbund I Danmark v Dansk Arbejdsgiveforening) [1991] ICR 74 was that the HSE did not have to justify any pay difference arising from the service criterion. It was to be assumed that a differential related to length of service was justified.[7]In Danfoss the employers paid individual supplements over and above basic rate of pay by reference to a whole series of criteria, including the employees' adaptability to variable hours and varying places of work, the quality of their work, their training, and length of service. The application of these criteria was opaque and it was not possible to determine which criteria had been applied to any particular employee. The evidence was that female employees on average were paid less than male employees. It was alleged that the system of pay was discriminatory.[8]The ECJ held that, in view of the statistics which demonstrated that on average females were paid 6 per cent less than males; the burden was on the employers to show that the system of pay was not discriminatory. The court held that when considering criteria such as variable hours, places of work and training, the employers needed to show that such adaptability or training was important in the performance of the specific tasks which the employee was entrusted to do. However, in relation to use in the length of service, it did not consider that the same requirement was applicable. The ECJ said this (para 24 of the decision):
"… As regards the criterion of length of service, it is also not to be excluded, as with training, that it may involve less advantageous treatment of women than men insofar as women have entered the labour market more recently than men or more frequently suffer an interruption of their career. Nevertheless, since length of service goes hand in hand with experience, and since experience generally enables the employee to perform his duties better, the employer is free to reward it without having to establish the importance it has in the performance of specific tasks entrusted to the employee."
[9]Before the Employment Tribunal in this case had reached its determination, but after it had heard all the evidence, the EAT (HH Judge Burke QC presiding) gave its decision in a related case of Cadman v HSE [2004] ICR 378 . That case involved HSE workers at grade 2, rather than grade 3, but was in other respects on all fours with this case. The EAT concluded in Cadman that Danfoss meant that with respect to full time workers it was not necessary for an employer to have to justify a pay difference resulting from the application of length of service criterion. An employer could adopt that criterion without having to provide any special justification.[10]In the light of that decision, the Employment Tribunal inevitably concluded that Mrs Wilson's claim must fail since everyone agreed that for some period of time at least pay could properly be made referable to length of service because of the additional experience that this conferred. However, the Employment Tribunal went on to consider what their decision would have been had Danfoss not barred their inquiry.[11]They expressed the view that they would have concluded that the ten-year period was not justified. They were persuaded by the evidence of Mr Strawson, the trade union official, that five years was sufficient. By that stage all inspectors of this grade would have reached the requisite skill. To the extent that the pay scale provided for a ten-year progression, it was five years more than could be justified by the value which experience added to the job. The Tribunal recognised that the evidence on which they relied was somewhat sparse and anecdotal, but they emphasised that in reaching that decision they had in mind that there was no absolutely correct answer and that there was a margin within which they would not interfere. So if, for example, they had found that eight or nine years was appropriate, they might have considered the ten year period justified.[12]The claimant appealed the decision of the Employment Tribunal. That appeal was stayed because Cadman had by then been appealed to the Court of Appeal who had in turn made a reference to the ECJ.[13]The proper interpretation of the ruling of the ECJ is now critical to this appeal, so the context in which that decision was reached needs to be considered. The Court of Appeal, when referring the case (see [2005] ICR 1546 ), noted that since Danfoss there had been a number of part time cases which appeared to have cast doubt on the continuing vitality of the principle enunciated in that case. These were Nimz v Freie und Hansestadt Hamburg [1991] ECR I -297 , Hill v Revenue Commissioners [1999] ICR 48 , and Gerster v Freistaat Bayern [1998] ICR 327.[14]Maurice Kay LJ, giving the judgment of the court, noted that these cases were difficult to reconcile with Danfoss , and suggested that maybe Danfoss had been the subject of second thoughts. He also observed that it was difficult in principle to see why an exception to the normal principle of justification should be adopted for length of service cases. However, given that the matter was not free from uncertainty, the court considered it appropriate to refer the issue to the ECJ. The terms of the first two questions were as follows:
"(1) Where the use by an employer of the criterion of length of service as a determinant of pay has a disparate impact as between relevant male and female employees, does article 141 EC require the employer to provide special justification for recourse to that criterion? If the answer depends on the circumstances, what are the circumstances? (2) Would the answer to the preceding question be different if the employer applies the criterion of length of service on an individual basis to employees so that an assessment is made as to the extent to which the greater length of service justifies a greater level of pay?"
[15]The Advocate General analysed the case law in some detail, and broadly agreed with the tentative views expressed by the Court of Appeal (see [2006] ICR 1623 ). He stated that he saw no justification for a general and unconditional endorsement of a seniority criterion. He also rejected a submission from the United Kingdom Government to the effect that in length of service cases the onus should initially be on the employee to show that a wholly disproportionate weight had been given to that criterion, and that the burden would then shift to the employer to demonstrate specific justification.[16]The Advocate General did, however, emphasise that the burden on the employer would be satisfied by demonstrating that the criterion itself was justified; it was not necessary to go further and provide justification for the difference in treatment between specific workers which may arise as a result of the application of that criterion. We take that to mean that he did not think that it had to be established in any specific case that length of service had in fact led to greater ability to do the job in question by the applicant or comparator; that could be assumed without proof.[17]However, the Advocate General went on to consider a third question, which was whether if he were to change the law as it had been understood since Danfoss , it was desirable to treat the new law as only applying from the date of the decision. This has exceptionally been done by the European Court such as in the Barber case. He agreed that that was a justified step to take in this case because many pay structures adopted a length of service criterion as a justification for pay differentials.[18]The ECJ did not follow the approach of the Advocate General. The ECJ concluded that in general it was not necessary to prove that length of service justified a difference in pay but that there would be an exception to that in circumstances where the claimant raised evidence capable of giving rise to serious doubts about whether it was appropriate. Since much turns on the actual language used by the court, it is necessary to set out the relevant paragraphs (paras 33-40):
" Recourse to the criterion of length of service 33 In Danfoss [1991] ICR 74, paras 24 and 25, the court, after stating that it is not to be excluded that recourse to the criterion of length of service may involve less advantageous treatment of women than of men, held that the employer does not have to provide special justification for recourse to that criterion. 34 By adopting that position, the court acknowledged that rewarding, in particular, experience acquired which enables the worker to perform his duties better constitutes a legitimate objective of pay policy. 35 As a general rule, recourse to the criterion of length of service, is appropriate to attain that objective. Length of service goes hand in hand with experience, and experience generally enables the worker to perform his duties better. 36 The employer is therefore free to reward length of service without having to establish the importance it has in the performance of specific tasks entrusted to the employee. 37 In the same judgment, the court did not, however, exclude the possibility that there may be situations in which recourse to the criterion of length of service must be justified by the employer in detail. 38 That is so, in particular, where the worker provides evidence capable of giving rise to serious doubts as to whether recourse to the criterion of length of service is, in the circumstances, appropriate to attain the above-mentioned objective. It is in such circumstances for the employer to prove that that which is true as a general rule, namely that length of service goes hand in hand with experience and that experience enables the worker to perform his duties better, is also true as regards the job in question. 39 It should be added that where a job classification system based on an evaluation of the work to be carried out is used in determining pay, it is not necessary for the justification for recourse to a certain criterion to relate on an individual basis to the situation of the workers concerned. Therefore, if the objective pursued by recourse to the criterion of length of service is to recognise experience acquired, there is no need to show in the context of such a system that an individual worker has acquired experience during the relevant period which has enabled him to perform his duties better. By contrast, the nature of the work to be carried out must be considered objectively: Rummler [1986] ECR 2101, para 13. 40 It follows from all of the foregoing considerations, that the answer to the first and second questions referred must be that article 141 EC is to be interpreted as meaning that, where recourse to the criterion of length of service as a determinant of pay leads to disparities in pay, in respect of equal work or work of equal value, between the men and women to be included in the comparison, (i) since, as a general rule, recourse to the criterion of length of service is appropriate to attain the legitimate objective of rewarding experience acquired which enables the worker to perform his duties better, the employer does not have to establish specifically that recourse to that criterion is appropriate to attain that objective as regards a particular job, unless the worker provides evidence capable of raising serious doubts in that regard; (ii) where a job classification system based on an evaluation of the work to be carried out is used in determining pay, there is no need to show that an individual worker has acquired experience during the relevant period which has enabled him to perform his duties better."
[19]In the light of that decision, the Wilson appeal before the EAT was successful to the extent that the case was remitted back to the Tribunal to determine whether or not the employee had provided evidence capable of raising serious doubts such as to justify the Tribunal having to consider the issue of justification in the particular circumstances. That was the context in which the Employment Tribunal promulgated its second decision.[20]On this second occasion, the Employment Judge carried out an extremely thorough examination of the history of the Cadman litigation and the decisions of the Advocate General and the full court. The Tribunal did not hear any further evidence, by agreement with the parties, but reached its conclusion on the question whether the evidence was capable of raising serious doubts as regards the job in question on the basis of the earlier evidence and the submissions made to it.[21]The arguments advanced before the Tribunal mirrored those advanced before us. .Essentially the claimants were alleging that Cadman had altered Danfoss . The ECJ had plainly concluded that the Tribunal could in an appropriate case - where evidence capable of raising serious doubts had been adduced by the claimant - require the employer to justify applying the length of service criterion to a particular job. Logically, its decision should also be read as entitling a tribunal to consider whether the application of the criterion was justified in the particular circumstances of the case. That opened up the possibility of testing whether the period for which it was applied was justified.[22]The HSE submitted that this proposition was unsustainable. Properly analysed, Cadman had merely made a small variation to the Danfoss decision. The ECJ itself said that it was only "clarifying" the decision. Whilst in exceptional cases Cadman enabled a tribunal to question whether the kind of job was one to which length of service criterion could properly be applied, it did not justify any further inquiry to consider whether it was applied proportionately in any particular case.[23]The Employment Judge commented, with some justification, that the reasoning in the European Court of Justice's judgment in Cadman was "disappointingly sparse" and that this "enigmatic judgment" required careful interpretation. Although the Tribunal plainly had considerable sympathy for the claimant, they ultimately felt compelled to conclude that they could not question the application of the length of service criterion. They accepted the HSE's submission that Cadman represented only a marginal departure from Danfoss , and that once it was accepted that the length of service criterion had been appropriately applied to the jobs in question, the manner of its application was beyond judicial scrutiny. The appeal .[24]The real issue to be determined is this: once it is accepted that the nature of the job is such that pay can properly be made to depend on length of service, is that the end of the Tribunal's enquiry, or can it also consider in an appropriate case whether the degree of recourse to length of service (and therefore, experience) can be justified? As we have seen, the Employment Tribunal concluded that it could not.[25]Ms Gill contends that this was a wrong interpretation of the ECJ decision. She submits that the Tribunal adopted an unduly literal interpretation of the ECJ's ruling. She focuses in particular upon paragraph 38 of the ECJ's decision which indicates that it is enough for the worker to raise serious doubts "as to whether recourse to the criterion of length of service is, in the circumstances , appropriate to attain the above-mentioned objective" (i.e of rewarding experience, which typically enables a worker to perform his duties better). She submits that the highlighted words entitle a tribunal to consider all aspects of the application of the criterion once the relevant doubts have been raised.[26]She rejects the Tribunal's assertion that if the enquiry could extend beyond determining whether in principle length of service was an appropriate criterion for the job, it would open up all length of service cases to judicial scrutiny. It was still necessary to show that there were serious doubts as to whether the criterion was justified.[27]She also submits, as a connected point, that it was wrong for the Tribunal to assert the claimant's contention would involve a fundamental departure from the basic principle enunciated in Danfoss . There would still be a very real area within which deference would have to be paid to an employer's view that experience and length of service went hand in hand.[28]Conversely, if the claimant was able to satisfy a tribunal that there were serious doubts as to whether the period of service to which payment was referable was such that it no longer bore any relation to the gaining of experience, then it would be at odds with the fundamental principle of equality to bar the tribunal from investigating that issue. There was no rationale in enabling a tribunal to review the question whether length of service was appropriate in any circumstances as a way of rewarding experience in a particular job, but barring it from considering the significance given to that factor in any particular case.[29]Ms Eady QC submits that the Tribunal's approach was correct. The careful analysis of the ECJ's decision in Cadman indicates that the ECJ was not intending any significant departure from the approach in Danfoss . Indeed, the court said that it was only a clarification of that decision. It was important to note that the Advocate General's approach had been rejected by the court. The ECJ clearly felt that length of service was a characteristic which would in the normal case justify extra payment because of the experience which it would provide, and the assumption is that job holders will typically perform their jobs better with more experience.[30]It is only exceptionally that this will be untrue and the ECJ has placed the burden on the employee to raise evidence capable of giving rise to serious doubts as to whether it is true or not. Had the ECJ intended to go further and to entitle the Tribunal to enquire into the particular operation of the length of service criterion in circumstances where it was in principle acceptable, then it would surely have said so. In particular, it was important to note that the Advocate General in Cadman had recognised the significant impact which his judgment would have for pay structures generally. He had thought it necessary that any change in the law should operate prospectively. The ECJ had not taken that step, and that no doubt was because they did not think that they were making any significant departure from the Danfoss ruling.[31]Ms Eady accepts that on her analysis it would only be in very exceptional cases, such as relatively simple manual work cases, where serious doubts might be raised as to whether or not the question of length of service could properly be employed as a criterion relating to pay. However, she says that this is entirely consistent with the Court in Cadman intending simply to tweak the Danfoss tail. The alternative analysis proposed by the claimants would, as the employment tribunal accepted, significantly widen the range of cases where the employer would be compelled to justify adopting a length of service criterion. That would undermine the Danfoss ruling and could not in any sensible way be described as mere clarification.[32]As to the submission that paragraph 38 focussed on all the circumstances, that language was not replicated in para. 40 when the answers to the specific questions are set out. The answer simply states that the burden of specifically establishing justification only relates to the question whether it is appropriate to use the criterion "as regards a particular job." If it is, then it matters not how it is used to differentiate pay. Conclusion .[33]We have not found this straightforward. The ECJ in Cadman has not provided the clarity one would have desired in its judgment. However, we think the better view is that, contrary to the conclusion of the employment tribunal in this case, a tribunal can question whether the length of service criterion in its application is justified in circumstances where the employee has raised serious doubts as to whether it is or not.[34]We say this for three reasons in particular. First, in Cadman itself there was no acceptance - as there is in this case - that some differential based on length of service could be justified, at least until a certain level of experience had been attained. The claimant was submitting that the employers had to justify the differential in pay arising out of the application of the length of service criterion. This would involve the employers justifying not only the adoption of the criterion with respect to the particular job, but also the period in respect of which it continued to justify a difference in pay. Both those issues were therefore before the court in Cadman .[35]It is true that the ECJ did not in terms disentangle the two elements of the claim. If they did so at all it was only by implication in the language they used. In particular, Ms Eady suggests that in paragraph 40, where they state their conclusion, they only appear to relate the issue of justification to the question whether length of service is appropriate to the particular job.[36]We do not think that much is to be gained by analysing the precise language of ECJ decisions in this way. They do not use language with particular rigour. In any event, in paragraph 40 they do refer to the fact that their conclusion "follows from all the foregoing considerations", which lends some support to Ms Gill's submission that they were not intending to limit the scope of judicial inquiry in the way the HSE suggests.[37]Second, if the HSE are right then the ECJ has created a rebuttable presumption that the nature of the job is one which justifies pay being related to length of service in some way, but thereafter, an irrebuttable presumption that any relationship between pay and length of service, however apparently arbitrary and disproportionate it may be, is justified and beyond the scrutiny of the courts. We think it unlikely that the court intended to adopt such a position.[38]A third and related point is this. In our view, the gravamen of Cadman is that there is a strong presumption that experience, measured by length of service, contributes to job performance. The court clearly thought that the presumption should not be readily upset; but it recognised that it could be in an appropriate case. We do not see any rationale for limiting such a case to situations where there is a question whether any application of the criterion is justified without also permitting a consideration of the particular way in which the criterion is applied.[39]This plainly involves a departure from Danfoss , but not in our view a fundamental one. However, we do not think that there is any significance in the fact that the ECJ said that it was only clarifying Danfoss . As the Advocate General himself pointed out in this case (para 46) "it is only on very rare occasions that the court will expressly reverse its own case law". When will specific justification be required?[40]The difficult issue is what does the employee have to establish in order to put the burden on the employer specifically to justify the length of criteria? The language used by the court is that the claimant must provide evidence which is capable of raising serious doubts about the use of the criterion. This is, if one reads it literally, an extremely curious formulation. The claimant does not actually have to raise serious doubts in the mind of the tribunal, but merely adduce evidence which is capable of raising such doubts. It is as if the tribunal should ask itself: are we persuaded that there is evidence here that could, if we considered it carefully, cause us to have serious doubts as to whether the presumption (to put it colloquially) that experience improves performance is justified in relation to its application in this case?[41]We do not think that the court could conceivably have intended such a bizarre self-direction. We take it that the court is, in fact, envisaging that the tribunal or whichever other body it is that is determining this matter, will have to ask itself whether the worker has in fact raised serious doubts as to whether the length of service criterion is justified. It is not enough simply to raise the possibility that there are serious doubts, otherwise we would accept that the decision would significantly undermine the Danfoss approach, which in our view the ECJ was keen not to do.[42]Ms Gill submitted that in substance the ECJ here is applying the same test as is commonly applied in indirect discrimination cases when applying the principles in Igen v Wong . It was akin to the first stage in that test: was there evidence which could, in the absence of some explanation, entitle a tribunal to conclude that the criterion employed was not justified?[43]We do not think that this analogy is altogether apt. In our judgment, the ECJ is plainly seeking to establish a position where there is a presumption that length of service is to be equated with experience which in turn is likely to result in improved job performance. It is not enough that the tribunal will have some doubts as to whether that is truly the position; they must have serious doubts. This suggests to us that the hurdle is a high one.[44]If after hearing the evidence of the claimant the tribunal is of the view that there is a genuine issue as to whether justification could be established, that would not be enough. We think that the tribunal would have to be satisfied that in the light of the evidence adduced by the claimant there is real reason to suspect that the employer has stepped beyond the margins which can properly be afforded to employers when considering whether added experience typically improves job performance. No doubt in many, if not virtually all, such cases the employer will have real difficulty in justifying the application of the criterion but the ECJ has held that the employer must have that opportunity.[45]In short, although the language does not quite replicate the position adopted by the UK Government before the court when it said that the employee must adduce an "overwhelming case" that the length of service criterion cannot be justified, nonetheless it seems to us that the court has gone some way towards accommodating that position. How should we dispose of the case?[46]A vexing question is what we should now do with this case. It began in June 2002 and the claimant has long since retired. Neither party was at all eager, for obvious reasons, for a reference to the ECJ to be made.[47]The problem is this. The Tribunal looked at the question of serious doubts only by reference to whether the job was in principle one which could justify some differential based on length of service. Given the concession in the case, the Tribunal's answer was inevitable. What the Tribunal did not do, however, was to ask itself whether in the light of the evidence adduced by the employee, it had serious doubts whether the ten year period which HSE had adopted was justified. Were there serious doubts whether experience would not improve job performance for the whole of this period?[48]We agree with Ms Eady that it does not necessarily follow that because an employer in the event fails to justify the length of time when specifically required to do so, that this demonstrates that there must have been serious doubts about that matter. For the reasons we have given, we think that there will be a category of cases where the employer might not be able specifically to justify if called upon to do so, but where the presumption of regularity, if we may so describe it, would not have been displaced to require the employer specifically to justify at all.[49]We have considered whether it would be appropriate for us in the light of the Tribunal's express findings of fact in the first decision to determine whether they would necessarily have concluded that there was serious reason to doubt the criterion adopted. We would do that if we thought that there was only one answer to the question but we do not think that we can safely take that course. The Tribunal itself indicated that if the period were perhaps 7 or 8 years it would not have found the period unjustified. That might possibly suggest that if the period were a bit longer then whilst it would have had doubts, these would not necessarily have been serious doubts as to the justification for the 10 year period.[50]It follows that in our view the relevant question has never really been identified or answered by the Tribunal. With very great reluctance, particularly bearing in mind the time which this case has already taken, we think we have little option but to refer the matter back to a tribunal to consider this issue of serious doubts again.[51]We have considered whether to send the matter back to the same Tribunal. That Tribunal has made detailed findings of fact in the case. We pay tribute to both the decisions, which are of conspicuous quality, albeit that we have not in the event agreed with the Tribunal's conclusion as to the meaning of Cadman . We think, however, that it would be asking too much for any tribunal that has made the findings which this Tribunal has now to be able to stand back and ask itself whether, having regard to the employee's evidence, it has serious doubts as to whether the criterion was lawfully applied. It will be almost impossible for it to insulate itself from the conclusion it has already reached that the differential was not justified.[52]The issue also arises whether we simply refer back the serious doubts question or the whole issue of justification. The latter question has, after all, been considered in detail by the Tribunal, albeit as an alternative finding in its original decision. An argument in favour of referring the whole issue back is that the evidence which the fresh tribunal hears on this preliminary issue of serious doubts may be different to the evidence adduced last time on justification, and it may be said that the two questions are inextricably interlinked. As against that, the case has been going on for over seven years and it may be difficult this far removed from events satisfactorily to adduce all relevant evidence before the tribunal, and that exercise has already been done.[53]Not without reservations, we have come to the conclusion that this issue of serious doubts alone must be referred back to another tribunal. If the HSE succeeds on this point, the claimant's case will fail, but otherwise this tribunal's finding on justification stands. (We should record, however, that this finding that there was no justification is subject to a cross appeal which has been stayed pending this appeal being determined. The cross appeal has not even been sifted. It will need to be dealt with if the fresh tribunal finds in the claimant's favour.) The appropriate procedure.[54]The Cadman decision (or at least our interpretation of it) has thrown up one further point of difficulty. What procedure should a tribunal adopt when considering this issue? This is less of a problem in this case than in one where the issue of justification itself is in issue.[55]Generally, it is desirable that a tribunal hears all the evidence on all the issues before it before reaching conclusions on any of them. There are often difficulties in trying to compartmentalise the evidence, hearing different aspects at different times. However, we think that the logic of the ECJ decision requires the Tribunal to depart from that approach and not hear all the evidence on justification before reaching its decision on the preliminary issue of serious doubts. Requiring all the evidence to be adduced in one go would undermine one of the objectives of Cadman , namely to relieve an employer of the task of having to adduce evidence to justify the differential unless there are serious doubts. It might also in practice be more difficult for the tribunal to distinguish the issue of serious doubts from the distinct issue of justification.[56]We do not envisage any restriction on the evidence which the worker can adduce, but we suspect that the more detailed the evidence, the more likely it is that the Tribunal will conclude that if such evidence needs to be adduced to establish serious doubts, then it is not a sufficiently obvious case for the burden to shift. It may be necessary for the employer to call witnesses, but only, we would have thought, to challenge any factual matters advanced by the employee. If this were not permitted, an employee could raise serious doubts by making a series of false assertions about, for example, the nature of the job being performed. Moreover, a tribunal might consider in any particular case that fairness requires that evidence on other matters should be adduced also. It would be wrong to be unduly prescriptive. Disposal .[57]The appeal succeeds, and we remit the issue of serious doubts to a fresh tribunal. This is a matter which needs to be speedily heard, given the length of time since the claim was lodged.