Omar Qureshi, Dan Tench and Cathryn Hopkins of CMS comment on the decision which was handed down on 15 May 2019 by the UK Supreme Court in the matter of R (Privacy International) v Investigatory Powers Tribunal and others [2019] UKSC 22: 

On 15 May 2019, the Supreme Court handed down its judgment, deciding by a slim majority of 4:3 that an “ouster clause” in the Regulation of Investigatory Powers Act 2000 , s 67(8)that purports to exclude from challenge or appeal any decision of the Investigatory Powers Tribunal (“IPT”), does not prevent a judicial review challenge based on an error of law.

Further, the majority commented (albeit obiter) that there was a “strong case” for finding that the rule of law requires that the courts should decide the extent to which to uphold a clause laid down by Parliament that purports to exclude the availability of judicial review by the High Court.

This case is likely to be a seminal one in the development of constitutional law and has already created much debate amongst academics and practitioners alike due to it (arguably) watering down the concept of Parliamentary sovereignty, while strengthening the constitutional separation of powers between legislature, executive and judiciary. From a more practical perspective is it likely to open up opportunities to claimants to challenge other “ouster” clauses in legislation, despite the authoritative dissenting judgments of Lord Sumption (with whom Lord Reed agreed) and Lord Wilson.


The appeal in R (Privacy International) v Investigatory Powers Tribunal & Ors [2019] UKSC 22, concerned primarily the issue of whether the High Court has jurisdiction to judicially review decisions of the IPT, despite the apparent exclusion of such jurisdiction by way of s 67(8) of the 2000 Act.

The IPT is a statutory tribunal that hears cases regarding the conduct of the security services. It was set up by statute to provide a review and oversight mechanism that allowed the conduct of the security services to be reviewed without any risk to national security caused by the normal public nature of court challenges. Back in 2016, charity Privacy International (“PI”) had brought a challenge before the IPT against computer surveillance activities carried out by GCHQ. IPT decided that such activities had been a lawful use of its powers pursuant to s.5 of the Intelligence Services Act 1994. PI then sought to challenge the IPT’s finding as an error of law before the High Court. However, that court held that s 67(8) of the 2000 Act excludes its jurisdiction to review decisions of the IPT. Section 67(8) provides as follows (emphasis added):

“Except to such extent as the Secretary of State may by order otherwise provide, determinations, awards, orders and other decisions of the Tribunal (including decisions as to whether they have jurisdiction) shall not be subject to appeal or be liable to be questioned in any court.”

The High Court’s decision was upheld by the Court of Appeal. PI then appealed to the Supreme Court. The questions for determination were:

  1. Whether s 67(8) “ousts” the supervisory jurisdiction of the High Court to quash a judgment of the IPT for error of law?
  2. Whether, and if so, in accordance with what principles, Parliament might by statute “oust” the supervisory jurisdiction of the High Court to quash the decision of an inferior court or statutory tribunal of limited jurisdiction?

The Supreme Court’s Decision

First Question

The Supreme Court considered this question as a matter of construction.

In allowing PI’s appeal, the majority (Lord Carnwath, with whom Lady Hale and Lord Kerr agreed, and Lord Lloyd-Jones) held that there was no “ouster” of the High Court’s jurisdiction to review a decision of the IPT for an error of law and that s 67(8) would have to include clearer wording in order to oust judicial review by the High Court, for example, by including “purported” determinations within its remit.

Relying on R (Cart) v The Upper Tribunal [2011] UKSC 28, the majority noted that there is a strong interpretative presumption against the exclusion of judicial review, other than by “the most clear and explicit words” (Laws LJ in Cart at the Court of Appeal). Lord Carnwath clarified that this presumption against ousting the supervisory role of the High Court over other adjudicative bodies was the case even with bodies established by Parliament with “apparently equivalent status and powers to those of the High Court” [99].

Lord Carnwath traced the case law on “ouster” clauses back to Anisminic Ltd v Foreign Compensation Commission [1969] 2 AC 147, the widest reading of which was summarised by Lord Diplock in O’Reilly v Mackman [1983] 2 AC 279 as follows (emphasis added):

“…if a tribunal whose jurisdiction was limited by statute or subordinate legislation mistook the law applicable to the facts as it had found them, it must have asked itself the wrong question, i.e. one into which it was not empowered to inquire and so had no jurisdiction to determine. Its purported ‘determination’, not being a ‘determination’ within the meaning of the empowering legislation, was accordingly a nullity”.

In Lord Carnwath’s view, the provision in s 67(8) for a route of appeal to the Secretary of State did not add anything, given that that power had not been exercised and was ultimately an executive power, so did not support the argument that the courts should not have ultimate control [104].

Therefore, as a matter of construction, the majority found that the wording in s 67(8) was not explicit enough to exclude judicial review, although did suggest that a more explicit formula might have excluded challenges to any determination or “purported determination” as “a nullity by reason of lack of jurisdiction, error of law, or any other matter” [111].

Lord Carnwath was not convinced by arguments about the importance of keeping the cases before the IPT protected in the interests of national security; he was satisfied that the Administrative Division of the High Court is capable of putting in place sufficient protections to ensure that sensitive information is protected [112].

The dissenting judgments of Lords Sumption and Wilson were to the effect that s 67(8) of the 2000 Act was clear in ousting the Court’s jurisdiction and that the rule of law was “sufficiently vindicated” by the judicial character of the IPT [172]. Lord Sumption also considered that the part in parenthesis in s 67(8) (emphasised above), which includes within the “ouster” clause challenges to decisions of the IPT as to whether it has jurisdiction, was included by the Parliamentary draftsman expressly to address the Anisminic judgment, and was sufficient to oust the court’s jurisdiction even in respect of errors of law. Lord Wilson was of a similar view.

However, Lord Sumption considered that while s 67(8) was clear enough to oust a review of the IPT’s substantive decision (i.e. a merits review), if there were manifest, procedural failings then the ouster clause would not apply [205]. So even the dissenting judgment did not completely rule out a means of challenge in certain circumstances.

Second Question

Given the majority’s finding in response to the first question, the second question did not require answering and the justices comments on this issue are obiter. The justices were also divided as to how to answer this question, with Lord Kerr and Lady Hale agreeing with Lord Carnwath; Lords Lloyd-Jones, Reed and Sumption declining to give a view; and Lord Wilson dissenting.

Lord Carnwath summarised the dispute on the second issue as being whether Parliament, consistently with the rule of law, has the power to entrust a task such as independent judicial review to a tribunal such as the IPT, “free from any possibility of review by the ordinary courts (including appellate courts)”. Lord Carnwath cited Cart as confirming that it is ultimately for the courts, not the legislature, to determine the limits set by the rule of law to the power to exclude review [131].

Lord Carnwath held that within the rule of law, the constitutional roles of Parliament (as the maker of law), and the courts (as guardians and interpreters of that law) have to be respected, and that the scope of judicial review required to maintain the rule of law should be a question for the courts [132].

In a comment that is likely to be cited ad infinitum, Lord Carnwath said (emphases added):

“I see a strong case for holding that, consistently with the rule of law, binding effect cannot be given to a clause which purports wholly to exclude the supervisory jurisdiction of the High Court to review a decision of an inferior court or tribunal, whether for excess or abuse of jurisdiction, or error of law. In all cases, regardless of the words used, it should remain ultimately a matter for the court to determine the extent to which such a clause should be upheld, having regard to its purpose and statutory context, and the nature and importance of the legal issue in question; and to determine the level of scrutiny required by the rule of law[144].

While Lord Sumption said that it was not appropriate to give a view on the second question as the answer may vary according to statutory context [207], Lord Wilson said that the answer to the second question must be “yes” [253]. This was on the basis that, in the case of the IPT, Parliament had intended it to be a judicial body with independence and authority. Its President has to hold or have held high judicial office (the post is currently held by Lord Justice Singh), its other members must hold or have held high judicial office or be UK lawyers of at least seven years’ qualification, and the IPT has to apply judicial review principles in exercising its jurisdiction. Furthermore, the IPT has its own conduct provisions, is separate from HMCTS and has total autonomy and, as per Laws LJ in R (A) v Director of Establishments of the Security Service [2010] 2 AC 1, the IPT was “a judicial body of like standing and authority to the High Court” [246] to [253].


While the general presumption against “ouster” clauses was already established prior to this case, the Supreme Court has recalibrated the delicate balance of the rule of law, interpreting s 67(8) of the 2000 Act in such a way that arguably goes against Parliament’s clear intention. Indeed, it will be of note to see how the majority’s obiter suggestion that Parliament would never be able to exclude the jurisdiction of the High Court to review the decision of an inferior court or tribunal is approached in future judgments in the face of an even clearer ouster clause than that in s 67(8).

As regards the general approach captured in the quotation from Lord Carnwath set out above, on one level this is perhaps uncontroversial. It is of course for the Court to determine the extent to which an ouster clause restricts review or appeal in any particular situation. But what is strikingly absent from this formulation is any reference to the intention of Parliament. Traditionally, it would have been that intention which would have been the touchstone in determining the court’s approach to interpreting any ouster clause, as indeed it would be with any other statutory provision. This decision suggests that in the future, courts will be guided by other factors and that is why commentators are saying that this may abrogate the sovereignty of Parliament, at least as regards the question of ouster clauses.

The majority’s decision was that the rule of law risks being undermined if Parliament has the power to alter the normal modes of judicial scrutiny of a decision of the executive so that it is undertaken by a “judicial body” that is not the High Court. However, if in future there is an even clearer ouster clause to which the court declines to give binding effect there may be questions as to whether the court has overstepped its own role within the rule of law. (Parliamentary sovereignty had hitherto been considered to be a component part of the rule of law.) Indeed, a showdown of this kind may be more likely in light of the construction-based determination of this particular appeal and one might now expect Parliament to amend s 67(8) to close the loophole that this judgment identifies.