Introduction
The United Kingdom’s constitution is often characterised by the tension between two of its core principles: Parliamentary Sovereignty and the Rule of Law. While Parliamentary Sovereignty suggests that Parliament holds ultimate legal authority and can legislate on any matter, the Rule of Law demands that state power is not arbitrary and that all, including government, are subject to the law. Judicial review is the primary legal mechanism through which the courts uphold the Rule of Law, by scrutinising the legality of actions taken by public bodies. Ouster clauses, which are statutory provisions that attempt to exclude or limit the jurisdiction of the courts to conduct judicial review, represent a direct legislative challenge to this mechanism. This essay will argue that ouster clauses and other statutory limits on judicial review do fundamentally undermine the Rule of Law. It will contend that while Parliament has the sovereign power to enact such clauses, the judiciary has consistently resisted them through a specific method of statutory interpretation, viewing the courts' supervisory jurisdiction as a constitutional fundamental. This has created an ongoing constitutional dialogue between the courts and Parliament, with the judiciary acting as the defender of the Rule of Law against legislative attempts to create legal black holes.
The Rule of Law and the Function of Judicial Review
The Rule of Law is a concept with a rich history and multiple interpretations, but its core idea is the supremacy of regular law over arbitrary power. A.V. Dicey, a prominent constitutional theorist, outlined three key aspects of the Rule of Law: the absence of arbitrary power on the part of the state; equality before the law; and the protection of individual liberties through the common law (Dicey, 1915). A more contemporary definition offered by Lord Bingham in his seminal work on the topic includes the principle that "all persons and authorities within the state, whether public or private, should be bound by and entitled to the benefit of laws publicly and prospectively promulgated and publicly administered in the courts" (Bingham, 2010, p. 8). A crucial element of this is that there must be a mechanism for resolving legal disputes and holding public bodies to account.
Judicial review serves as this primary mechanism in UK public law. It is not an appeal on the merits of a decision, but a review of the process by which a decision was made. The courts assess whether a public body has acted within its powers (intra vires) or exceeded them (ultra vires). The grounds for judicial review, famously categorised by Lord Diplock in the GCHQ case, are illegality, irrationality, and procedural impropriety (Council of Civil Service Unions v Minister for the Civil Service [1985] AC 374). By ensuring that decision-makers act lawfully, rationally, and fairly, judicial review gives practical effect to the Rule of Law. It ensures that the executive is not above the law and that citizens have a legal avenue to challenge the unlawful exercise of state power. Therefore, any attempt to limit or exclude judicial review is, by extension, an attack on the practical application of the Rule of Law.
Ouster Clauses as an Expression of Parliamentary Sovereignty
Standing in direct opposition to the Rule of Law is the doctrine of Parliamentary Sovereignty. This principle, also heavily articulated by Dicey, traditionally holds that Parliament has the power to make or unmake any law whatsoever, and that no person or body, including a court of law, can override or set aside the legislation of Parliament. From this perspective, if Parliament, as the supreme legislative body, chooses to include a provision in a statute that prevents the courts from reviewing a particular decision or action, then the courts are constitutionally bound to obey that command.
Ouster clauses are the legislative tools used to achieve this exclusion. They can be drafted as "total" ousters, which seek to remove all judicial oversight, or "partial" ousters, which might impose strict time limits for bringing a challenge or limit review to certain grounds. A typical example of wording for a total ouster clause is found in the Foreign Compensation Act 1950, which stated that a "determination by the commission of any application made to them under this Act shall not be called in question in any court of law." On a literal reading, this language appears to be an unambiguous instruction from Parliament to the courts to refrain from any form of review. The constitutional justification for such clauses is that Parliament has delegated decision-making power to a specific body and decided that this body, not the courts, should have the final say, perhaps for reasons of expertise, speed, or policy.
The Judicial Response: Interpreting Ousters to Protect the Rule of Law
Despite the clear wording of many ouster clauses, the judiciary has developed a strong presumption that Parliament does not intend to exclude the jurisdiction of the courts to correct errors of law. The landmark case that established the modern judicial approach is Anisminic Ltd v Foreign Compensation Commission [1969] 2 AC 147. The case concerned the ouster clause in the Foreign Compensation Act 1950 mentioned above. The House of Lords was faced with a direct conflict: the seemingly absolute ouster clause on one hand, and a decision from the Commission that was, Anisminic argued, based on an error of law on the other.
Instead of declaring the clause unconstitutional (which would be a direct challenge to Parliamentary Sovereignty), the Law Lords performed a feat of interpretation. They reasoned that the clause only protected a "determination" from being questioned. A decision that was made with an error of law (a misinterpretation of the legal rules the Commission was supposed to apply) was not a real "determination" in the eyes of the law. It was a "purported determination" or a nullity, and therefore fell outside the protection of the ouster clause. Lord Reid stated that there was a presumption that ouster clauses did not prevent review of a decision that was a nullity. This approach allows the courts to maintain their supervisory role while formally respecting the language of the statute. In reality, it renders most ouster clauses ineffective against review for errors of law, as any such error makes the decision ultra vires and thus a "nullity" reviewable by the courts.
This principle has been consistently applied and was recently affirmed by the Supreme Court in R (Privacy International) v Investigatory Powers Tribunal [2019] UKSC 22. This case concerned section 67(8) of the Regulation of Investigatory Powers Act 2000, which stated that decisions of the Investigatory Powers Tribunal "shall not be subject to appeal or be liable to be questioned in any court." The government argued this extremely clear language was sufficient to oust the High Court's jurisdiction. However, the majority of the Supreme Court, applying the Anisminic principle, held that this wording was not sufficient to exclude review for errors of law. Lord Carnwath asserted that it would take "the most clear and explicit words" for Parliament to succeed in ousting review, and even then, there was a question as to whether it was constitutionally possible at all. This judgment confirms that judicial review is seen by the courts as a fundamental constitutional principle that will be fiercely protected.
Modern Limits and the Continuing Tension
The ongoing constitutional struggle is evident in modern legislative trends. While the courts have established a strong defence against traditional ouster clauses, Parliament continues to explore ways to limit judicial review. This can be seen as an attempt by the executive and legislature to reassert control over areas of public policy. For example, the Judicial Review and Courts Act 2022 introduced changes to the remedies available in judicial review, creating a "presumption" in favour of suspended or prospective-only quashing orders. Critics argue that this weakens the power of judicial review by allowing an unlawful government action to remain legally valid for a period, thereby diluting the remedy for the successful claimant and undermining the immediate correcting effect of a court's ruling (Elliott, 2021).
Furthermore, Parliament has not given up on drafting stronger ouster clauses. Section 5(1) of the Illegal Migration Act 2023, for example, contains a clause relating to interim measures from the European Court of Human Rights, stating that it is for a Minister of the Crown alone to decide whether to comply. While not a classic ouster, it seeks to ring-fence a specific governmental decision from binding legal oversight. This demonstrates that the tension between Parliamentary Sovereignty and the Rule of Law is not a historical issue but a live and evolving one. The government's Independent Review of Administrative Law (2021) considered more radical options for ousting judicial review in certain areas, indicating a continued executive desire to limit judicial scrutiny. While the government did not adopt the most extreme proposals, the debate itself highlights the precarious balance. These legislative and policy moves show a clear intent to limit the courts' reach, which in turn limits the practical application of the Rule of Law by making it harder to hold the government to account.
Conclusion
In conclusion, ouster clauses and other statutory limits on judicial review undoubtedly undermine the Rule of Law in principle. They represent a direct attempt by the legislature to place the actions of public bodies beyond the scrutiny of the courts, violating the core principle that all are subject to the law. If effective, such clauses would create pockets of executive power immune from legal challenge, a situation that is fundamentally at odds with the Diceyan and Binghamite conceptions of a society governed by law rather than arbitrary power.
However, the constitutional story is more complex than this. In practice, the judiciary has mounted a remarkably successful defence of its supervisory jurisdiction. Through the powerful interpretive tool developed in Anisminic and reaffirmed in Privacy International, the courts have managed to neutralise the effect of most ouster clauses by holding that any decision based on an error of law is a nullity and not protected by the clause. This judicial stance demonstrates a deep-seated belief that the power to determine the limits of legal authority is a constitutional fundamental inherent in the judicial function itself. While Parliament can and does continue to test the boundaries with increasingly explicit legislative language and new forms of limitation, as seen in the Judicial Review and Courts Act 2022, the courts have so far held the line. Therefore, while ouster clauses represent a serious theoretical threat to the Rule of Law, their practical ability to undermine it has been significantly curtailed by a judiciary committed to its own constitutional role as the guardian of legality.
References
Bingham, T. (2010) The Rule of Law. Allen Lane.
Dicey, A.V. (1915) Introduction to the Study of the Law of the Constitution. 8th ed. Macmillan.
Elliott, M. (2021) 'The Judicial Review and Courts Bill: A wolf in sheep’s clothing?', Public Law for Everyone. [Online]. Available at: I am unable to provide a URL as I cannot verify the exact blog post, but this is a widely known commentary by Professor Mark Elliott.
Independent Review of Administrative Law. (2021) Independent Review of Administrative Law Report. [Online]. Available at: I am unable to provide a URL to the specific government publication page.
Cases
Anisminic Ltd v Foreign Compensation Commission [1969] 2 AC 147.
Council of Civil Service Unions v Minister for the Civil Service [1985] AC 374.
R (Privacy International) v Investigatory Powers Tribunal [2019] UKSC 22.
Legislation
Foreign Compensation Act 1950.
Illegal Migration Act 2023.
Judicial Review and Courts Act 2022.
Regulation of Investigatory Powers Act 2000.
