Joe Tomlinson & Katy Sheridan
King's College London, Public Law Project
Reading practitioner and academic texts on judicial review in the UK (with a few exceptions aside), it would be very easy to get the impression that the detailed assessment of evidence is no part—or at least not an important part—of judicial review. The long-favoured practitioner treatise—de Smith’s Judicial Review—only makes passing mention of evidence in a text which runs 1098 pages. Equally, looking at the Administrative Court’s Judicial Review Guide, there is only scant reference to the handling of evidence. Even the classic functionalist academic text, Law & Administration, does not include determining evidential questions in its list of the functions of judicial review. Our view is that any suggestion that judicial review in the UK has no significant evidence-assessing function ought to be rejected as artificial. Rather, the detailed assessment of a broad range of evidence is often an important aspect of judicial review and its significance appears to be growing. In this short blog, we will briefly explain where the requirement to assess evidence flows from, highlight how ‘systemic unfairness’ cases seem to present a more pronounced instance of such assessments, and suggest there is a need to build an empirical account of practice in this area.
The requirement, in some cases, to assess evidence in judicial review proceedings flows from the nature of public law principles and the task of applying those principles. For instance, take the principle of proportionality. This is almost a ‘generic’ principle of public law in many jurisdictions and in the UK it has a variety of definitions, but it is broadly asks: (a) whether a measure’s objective is sufficiently important to justify the limitation of a fundamental right; (b) whether a measure is rationally connected to the objective; (c) whether a less intrusive measure could have been used; and (d) whether, having regard to these matters and to the severity of the consequences, a fair balance has been struck between the rights of the individual and the interests of the community. It is clear, as Anne Carter has observed, that ‘judicial assessments of proportionality often depend upon complex empirical questions that are difficult to determine with any certainty.’ Mattias Kumm has further explained how both the suitability and necessity sub-tests involve empirical claims as they ‘express the requirement that principles be realised to the greatest possible extent relative to what is factually possible.’ Similarly, Aharon Barak has observed that:
In order to properly answer the question of whether the alternative means – which limit the right to a lesser extent – equally advance the purpose as the means chosen by the legislator, an understanding of both the purpose and the probability of its being achieved through the alternative means is necessary. An estimate is insufficient; the understanding should be of the concrete factual data, as well as of the probabilities and risks involved.
Others have made similar points. The courts have also recognised this aspect of their role. For instance, in Wilson v First County Trust Ltd  UKHL 2004 1 AC 816  it was said that:
"The questions of justification and proportionality involve a sociological assessment – an assessment of what are the needs of society. This in part involves a legal examination of the content and legal effect of the relevant provision. But it also involves consideration of what is the mischief, social evil, danger etc which it is designed to deal with. Often these matters may already be within the knowledge of the court. But equally there will almost always be other evidentially valuable material which can be placed before the court which is relevant, such as reports that have been made, statistics that have been collected, and so on. Oral witnesses may have important evidence too."
Yet, the dilemma of how facts are established under proportionality analysis has not widely been wrestled with by academics in the UK.
The need to undertake an assessment of evidence cannot be avoided by blaming the particular principle of proportionality either. For example, the same applies to the classic Wednesbury reasonableness test in English law, often contrasted with proportionality for being a more deferential standard of review. As Lord Diplock’s famous conceptualisation puts it, the test asks whether a measure is so ‘outrageous in its defiance of logic or accepted moral standards that no sensible person who had applied his mind to the question to be decided could have arrived at it.’ This standard, as Paul Craig has demonstrated, requires close consideration of the facts and a balancing of considerations—an exercise informed by evidence. Even cases of statutory interpretation—which is what the vast majority of judicial reviews in the UK concern and the most fundamental of judicial roles—involves close consideration of facts: in assessing whether government action is within the scope of a statutory provision, courts rely upon a range of facts or assumptions about facts.
The assessment of evidence through judicial review does not only exist but it has likely grown in the recent past too. The grounds of judicial review have multiplied in recent decades. The introduction of the Human Rights Act 1998, in particular, puts the courts—bound by a duty under Section 6 of that Act—in a position to interrogate facts closely. This role under the Human Rights Act was essentially handed to the courts by Parliament. However, judicial creativity which led to the evolution of new and more expansive common law grounds of review is also partially responsible for the development of the judicial review’s evidence-assessing function. For instance, the development of substantive legitimate expectations as a ground of review has led to a greater role for the courts in determining evidence in some cases.
The fact-finding role of the courts is particularly significant in systemic unfairness litigation. That is, cases where there is a claim that goes beyond attacking the legality of an individual decision (a type of case the UK courts have seen more and more of in recent decades). The evidence required and thus considered in the course of such claims—by their very nature—seeks to reach beyond the narrow circumstances of a single decision. Moreover, recent cases have seen social science research and expert analysis used as decisive evidence. Two recent examples demonstrate this. First, there is the widely reported Supreme Court judgement in UNISON. This case saw a ruling that struck down a fee for accessing employment tribunals. Data on the effects of the fee, produced and analysed by University of Oxford academics, was used in the litigation and was a key part of the ultimate decision. The Government estimates the total cost of fee refunds, including interest of 0.5%, will amount to £33m. The government has also been required to hire new judges to cope with revitalised demand on the tribunal. Second, there is the case of RF, which was a successful Administrative Court challenge to discrimination in social security policy. In RF, it was the evidence of the Department for Work and Pensions, used to justify a policy, that was under scrutiny. Mostyn J ruled that if ‘a distinction with such a dramatic effect is to be drawn [by the Department for Work and Pensions] then elementary fairness surely requires that empirical research be commissioned. In the absence of any empirical research the view is no more than a subjective opinion or hypothesis.’ He found the government’s research was a ‘red herring... I am satisfied, for the reasons I have given, that this discriminatory measure is not ‘rationally’ connected to its objective.’ After the decision in RF, the government decided not to appeal and instead to undertake a review of approximately 1.6 million benefits, with around 220,000 people expected to receive more money. In both UNISON and RF, social science evidence of different kinds, originating from different parties, was a central part of rulings that had large government-side impacts.
The importance of the assessment of evidence in the contemporary judicial review process is irrefutable, particularly in systemic unfairness cases. There is little clarity, however, on how the courts handle that function and the extent of its significance in practice. This lack of clarity is made more difficult by the fact that evidential issues in judicial reviews are often left out of judgments or not fully discussed. There is then, we suggest, an important need to develop an account of the practices around the use of evidence in judicial review, and particularly systemic unfairness judicial review. Only once we have a firmer grasp on the nature of this unfolding function of judicial review, can we have an informed debate about how it is working and what—if anything—ought to be done in this area.
We are grateful to participants at a Melbourne Law School Centre for Comparative Constitutional Studies seminar where this ongoing research was presented in August 2018.
Joe Tomlinson is a Lecturer in Public Law at King’s College London and a Research Director at Public Law Project.
Katy Sheridan is a Bonavero Fellow at Public Law Project.
Suggested citation: J Tomlinson and K Sheridan, 'Judicial Review, Evidence, and Systemic Unfairness in the UK' IACL-AIDC Blog (3 September 2018) https://blog-iacl-aidc.org/blog/2018/9/3/judicial-review-evidence-and-systemic-unfairness-in-the-uk