Privacy International, R (on the application of)v Investigatory Powers Tribunal & Ors

Factual and Procedural Background

The Appellant asked the Investigatory Powers Tribunal (IPT) to decide whether “Computer Network Exploitation” (CNE) conducted by the intelligence services was lawful. On 12 February 2016 the IPT, sitting with five legally-qualified members, dismissed the claim, holding that section 5(2) of the Intelligence Services Act 1994 permitted so-called “thematic” warrants authorising broad classes of hacking.

The Appellant sought judicial review of that ruling. The High Court (Divisional Court) held that section 67(8) of the Regulation of Investigatory Powers Act 2000 (RIPA) excluded judicial review. The Court of Appeal agreed. The Supreme Court (a seven-judge panel) heard a further appeal to determine whether the subsection really bars the supervisory jurisdiction of the ordinary courts and, if so, whether Parliament can validly legislate to that effect.

Legal Issues Presented

1. Does section 67(8) of RIPA validly oust the High Court’s supervisory jurisdiction to quash a determination of the IPT on grounds of error of law?
2. If it does, can Parliament, consistently with constitutional principle, lawfully exclude the High Court’s supervisory jurisdiction over a statutorily-limited tribunal?

Arguments of the Parties

Appellant’s Arguments

• Ouster clauses must be read strictly; after Anisminic any error of law renders a decision a nullity, so Parliament must use the clearest words to bar review—words which section 67(8) lacks.
• The parenthetical reference to “decisions as to whether they have jurisdiction” was meant only to protect findings of jurisdictional fact, not errors of law.
• Even if clear, a total exclusion of supervisory jurisdiction would offend the rule of law: some external court must remain able to correct legal error.
• Security-sensitive material can be protected in ordinary courts through closed-material procedures, so a complete ouster is unnecessary.

Respondent’s Arguments

• Section 67(8) expressly covers “decisions as to whether [the IPT] have jurisdiction” and therefore, by clear language, displaces review for errors of law.
• The IPT is a fully-fledged judicial body presided over by senior judges, created precisely to decide sensitive issues in closed conditions; Parliament was entitled to make its determinations final.
• The statutory context—special procedures, security considerations and the power (unused) to create an appeal mechanism—shows a deliberate policy choice to confine litigation to the IPT.

Intervener’s (Civil Liberties Group) Arguments

• The IPT’s remit goes far beyond intelligence matters; allowing it to develop “local law” without external oversight threatens consistency and the rule of law.
• Citizens would be left without a domestic remedy for blatant legal error, save for a long route to the Strasbourg court.

Table of Precedents Cited

Court's Reasoning and Analysis

Majority (Judges A, B and C and concurring members)

• Section 67(8) reproduces the classic Anisminic-style ouster but adds the words “(including decisions as to whether they have jurisdiction)”, a deliberate attempt to cover errors of law that Anisminic kept reviewable.
• Nevertheless the presumption against ouster is very strong; Parliament must use “the most clear and explicit” language to exclude review, and the subsection is ambiguous once read in its full statutory setting.
• The IPT performs a supervisory, quasi-High-Court function but that does not justify insulating it completely; overlap with ordinary courts (e.g., tort and Article 8 claims) makes external control essential to maintain consistent law.
• Security concerns, while weighty, can be managed by existing High Court procedures (e.g., closed-material process) and cannot justify a total bar.
• Historical analysis (from Cheltenham Commissioners through Cart) shows that, absent explicit wording, courts have never accepted that Parliament intended to create an unreviewable island of law.
• Accordingly, section 67(8) does not exclude the High Court’s supervisory jurisdiction; permission should be granted because the construction of section 5 of the 1994 Act is a matter of general public importance.

Dissent (Judges D and E)

• Section 67(8) is an explicit ouster: the parenthetical phrase was inserted precisely to neutralise the Anisminic approach; ordinary errors of law are included.
• The IPT is a judicial body of equivalent authority to the High Court within its specialist field; allowing review would create a duplicate appellate layer that Parliament deliberately rejected.
• The rule of law is satisfied by the existence of the IPT; the constitution does not require further appeal or review.
• Therefore the courts below were right; the appeal should be dismissed.

Holding and Implications

HELD: The appeal is allowed; section 67(8) of RIPA does not exclude the supervisory jurisdiction of the High Court, which therefore may entertain an application for judicial review of the IPT’s determination.

Implications: The decision re-opens the door to limited judicial review of IPT rulings, ensuring that important legal questions (e.g., the legality of “thematic warrants”) can reach the ordinary courts. While no new statutory right of appeal was created, the judgment affirms that, absent unmistakably explicit language, Parliamentary attempts to shield even high-level specialist tribunals from legal scrutiny will fail. Future legislation seeking to confer finality on tribunal decisions must confront this standard.