Introduction
The doctrine of parliamentary sovereignty is a cornerstone of the United Kingdom's uncodified constitution. It establishes the principle that the Westminster Parliament is the supreme legal authority in the UK, with the power to create or end any law. This essay will define the traditional concept of parliamentary sovereignty, primarily through the work of A.V. Dicey, and then discuss how the doctrine has been challenged and modified by developments in the contemporary constitutional landscape, including the UK's former membership of the European Union, the Human Rights Act 1998, and evolving judicial attitudes.
The Diceyan Conception of Sovereignty
The classic definition of parliamentary sovereignty was articulated by the constitutional theorist A.V. Dicey. In his work, An Introduction to the Study of the Law of the Constitution, Dicey (1915) outlined three key principles. Firstly, Parliament has the right to make or unmake any law whatsoever. This means there are no legal limits on the subject matter of an Act of Parliament. Secondly, no person or body, including the courts, has the authority to override or set aside the legislation of Parliament. This is known as the ‘enrolled bill rule’, where once a bill has passed through the required parliamentary stages and received Royal Assent, courts must apply it as valid law and cannot inquire into how it was passed (British Railways Board v Pickin [1974] AC 765). Thirdly, no Parliament can bind its successors or be bound by its predecessors. This ensures that the legislative power of the current Parliament remains absolute and cannot be limited by a previous Parliament attempting to entrench legislation. This principle is upheld by the doctrine of implied repeal, which states that where two Acts of Parliament conflict, the later Act is deemed to have implicitly repealed the earlier one to the extent of the inconsistency.
Challenges to the Traditional Doctrine
While the Diceyan model provides a clear definition, its absolute nature has been tested by several significant developments. A major challenge came from the UK's membership of the European Union (EU), initiated by the European Communities Act 1972 (ECA 1972). The landmark case of R v Secretary of State for Transport, ex p Factortame Ltd (No 2) [1991] 1 AC 603 demonstrated that UK courts were required to 'disapply' an Act of Parliament—the Merchant Shipping Act 1988—where it conflicted with EU law. This was a direct contradiction of the principle that no body could set aside parliamentary legislation. While it was argued that this was a voluntary and reversible delegation of power by Parliament, it nonetheless imposed a significant practical and legal limit on parliamentary supremacy for the duration of the UK's membership.
Furthermore, the Human Rights Act 1998 (HRA 1998) introduced another qualification. Section 3 of the HRA requires courts, so far as it is possible to do so, to read and give effect to primary legislation in a way which is compatible with the European Convention on Human Rights. If this is not possible, a higher court can issue a 'declaration of incompatibility' under section 4. While a declaration does not invalidate the Act, it places significant political pressure on Parliament to amend the legislation. As such, the HRA has created a new interpretative framework that constrains legislative power, even if it formally preserves sovereignty (Loveland, 2021).
Finally, some senior judges have questioned the absolute nature of the doctrine. In Jackson v Attorney General [2005] UKHL 56, which concerned the validity of the Hunting Act 2004, several Law Lords made obiter comments suggesting that there may be limits to parliamentary sovereignty. Baroness Hale questioned whether Parliament could legislate to abolish judicial review, stating that "the courts will treat with particular suspicion (and might even reject) any attempt to subvert the rule of law by removing governmental action affecting the rights of the individual from all judicial scrutiny". This hints at the possibility that the courts might, in extreme circumstances, refuse to recognise a statute that undermines fundamental constitutional principles.
Conclusion
In conclusion, the traditional Diceyan definition of parliamentary sovereignty, which asserts Parliament's unlimited legal power, remains a central theoretical principle of the UK constitution. However, its orthodox, absolute interpretation has been significantly qualified. The practical supremacy of EU law during the UK’s membership, the interpretative obligations imposed by the Human Rights Act 1998, and evolving judicial dicta in cases like Jackson demonstrate that sovereignty is not as absolute as Dicey described. These developments suggest that the doctrine has evolved from a simple statement of unlimited power into a more complex principle, subject to legal and political constraints which, while not formally overturning it, have reshaped its practical application in the modern UK constitution.
References
- Barnett, H. (2021) Constitutional and Administrative Law. 14th edn. Routledge.
- Dicey, A.V. (1915) An Introduction to the Study of the Law of the Constitution. 8th edn. Macmillan.
- Loveland, I. (2021) Constitutional Law, Administrative Law, and Human Rights: A Critical Introduction. 9th edn. Oxford University Press.
- British Railways Board v Pickin [1974] AC 765.
- Jackson v Attorney General [2005] UKHL 56.
- R v Secretary of State for Transport, ex p Factortame Ltd (No 2) [1991] 1 AC 603.
- European Communities Act 1972.
- Human Rights Act 1998.
