Introduction
The doctrine of parliamentary sovereignty is often described as the cornerstone of the United Kingdom’s uncodified constitution. Coined in its orthodox form by A.V. Dicey, it posits that the UK Parliament possesses absolute and unlimited legislative authority (Dicey, 1915). However, the latter half of the twentieth century and the beginning of the twenty-first have witnessed the rise of ‘modern constitutionalism’, a paradigm emphasising the limitation of state power through mechanisms such as the rule of law, the separation of powers, and the protection of fundamental human rights. This development creates an inherent tension, prompting a critical evaluation of whether a doctrine of unfettered legislative power can coexist with a constitutional order predicated on its restraint. This essay will argue that while the classical, absolute conception of parliamentary sovereignty is fundamentally incompatible with modern constitutionalism, the doctrine has not been discarded but has undergone a significant transformation. Through an analysis of the impacts of European Union membership, the Human Rights Act 1998, and the evolving jurisprudence of the UK judiciary, this essay will contend that parliamentary sovereignty has been recalibrated, resulting in a more complex, contested, and ultimately more modern constitutional settlement.
The Traditional Diceyan Orthodoxy
The traditional doctrine of parliamentary sovereignty, as articulated by Dicey, comprises three essential limbs: Parliament has the power to make or unmake any law whatsoever; no person or body has the authority to override or set aside an Act of Parliament; and no Parliament can bind its successor. This principle established Parliament’s supremacy over both the Crown and the judiciary, a settlement historically cemented by the Glorious Revolution and the Bill of Rights 1689. Under this orthodox view, the validity of an Act of Parliament is not a matter for the courts. This was affirmed in cases such as Pickin v British Railways Board [1974] AC 765, where the House of Lords refused to investigate allegations that Parliament had been misled during the passage of an Act, cementing the ‘enrolled bill rule’ which holds that once an Act receives Royal Assent and is placed on the parliamentary roll, its validity is beyond judicial question.
This absolute power, however, sits uneasily with the core tenets of modern constitutionalism, which presupposes that all state power, including legislative power, should be subject to legal limits to protect individual liberty and uphold the rule of law. As Lord Bingham (2010) argued, the rule of law requires the protection of fundamental rights, a principle that is conceptually difficult to reconcile with a legislature that possesses, in theory, the power to legislate away those very rights. It is this fundamental conflict that has been exposed and interrogated by several major constitutional developments.
The Challenge of European Union Membership
The UK’s accession to the European Economic Community in 1973, effected domestically by the European Communities Act 1972 (ECA 1972), presented the most significant constitutional challenge to Diceyan orthodoxy. Section 2(1) of the ECA incorporated directly effective EU law into the UK’s domestic legal system, while Section 2(4) stipulated that any UK enactment, past or future, was to be construed and have effect subject to the requirements of EU law. The implications of this became starkly apparent in R v Secretary of State for Transport, ex parte Factortame Ltd (No 2) [1991] 1 AC 603. In this landmark case, the House of Lords was required to suspend the application of a provision in a UK statute, the Merchant Shipping Act 1988, because it conflicted with EU law. This act of ‘disapplying’ a statute was unprecedented and appeared to be a direct contradiction of the principle that no body could set aside legislation enacted by Parliament.
Debate has raged over whether this constituted a true surrender of sovereignty. One perspective, advanced by Sir William Wade, argued that the ECA 1972 represented a political and legal revolution, whereby Parliament had accepted a new constitutional reality where EU law was a higher legal order (Wade, 1996). Conversely, the dominant judicial and political view held that sovereignty remained intact. Proponents of this view argued that Parliament had voluntarily chosen to accept the primacy of EU law and, crucially, retained the power to repeal the ECA 1972 at any time, thereby reasserting its ultimate supremacy. This was the ‘self-embracing’ or ‘continuing sovereignty’ theory, which viewed the ECA as a conduit for EU law that Parliament could, at any point, close off. The UK’s withdrawal from the EU, facilitated by the European Union (Withdrawal) Act 2018 which repealed the ECA 1972, can be seen as the ultimate vindication of this latter view. However, the Factortame episode irrevocably demonstrated that Parliament’s legislative authority could be legally subordinated to an external legal framework, altering the constitutional landscape and providing a powerful precedent for qualified, rather than absolute, sovereignty.
The Human Rights Act 1998 and the ‘New’ Judicial Role
A further, and more permanent, modification of the constitutional balance came with the Human Rights Act 1998 (HRA 1998). The HRA incorporates rights from the European Convention on Human Rights (ECHR) into domestic law, creating a novel framework for the relationship between Parliament and the judiciary. It consciously avoids a direct clash with parliamentary sovereignty by not granting courts the power to strike down primary legislation. Instead, it provides two key mechanisms. Section 3 requires courts, “so far as it is possible to do so,” to read and give effect to primary and subordinate legislation in a way that is compatible with Convention rights. This interpretive duty can be a powerful tool, as demonstrated in Ghaidan v Godin-Mendoza [2004] 2 AC 557, where the House of Lords reinterpreted the Rent Act 1977 to include same-sex partners, a reading that arguably went beyond Parliament’s original intent but was necessary to avoid discrimination.
Where such a compatible interpretation is not possible, Section 4 allows a higher court to issue a ‘declaration of incompatibility’. This declaration does not invalidate the legislation; it remains valid law unless and until Parliament decides to amend or repeal it. This ingenious device preserves Parliament’s formal legislative supremacy while creating significant political pressure to rectify the incompatibility. For example, following the declaration of incompatibility in A v Secretary of State for the Home Department [2004] UKHL 56 concerning the indefinite detention of foreign terrorist suspects, Parliament enacted the Prevention of Terrorism Act 2005. The HRA, therefore, establishes a constitutional ‘dialogue’ between the courts and Parliament (Elliott, 2011). While sovereignty is formally preserved, the judiciary is empowered to act as a guardian of fundamental rights, scrutinising legislation against a rights-based benchmark. This model is arguably more compatible with modern constitutionalism than the Diceyan absolute, as it institutionalises a check on legislative power without fully abandoning the UK’s democratic tradition of parliamentary supremacy.
The Rise of Common Law Constitutionalism
Perhaps the most profound challenge to the traditional doctrine has emerged from the judiciary itself, through the theory of ‘common law constitutionalism’. This theory posits that the rule of law is the ultimate controlling principle of the constitution, from which parliamentary sovereignty itself is derived and by which it is conditioned. This radical idea was most famously articulated in the obiter dicta of R (Jackson) v Attorney General [2005] UKHL 56. While the case itself concerned the validity of the Hunting Act 2004, several Law Lords took the opportunity to question the absolute nature of parliamentary sovereignty.
Lord Steyn remarked that “the classic account given by Dicey of the doctrine of the supremacy of Parliament…can now be seen to be out of place in the modern United Kingdom.” Lord Hope went further, stating, “Parliamentary sovereignty is no longer, if it ever was, absolute… The rule of law enforced by the courts is the ultimate controlling factor on which our constitution is based.” Baroness Hale similarly suggested that courts might one day have to confront the question of whether “a democratically elected legislature” could “abolish judicial review or the ordinary role of the courts”. These statements suggest that the judiciary might refuse to recognise an Act of Parliament that sought to undermine fundamental constitutional principles, such as access to the courts or the rule of law itself. This perspective frames sovereignty not as a political fact given to the courts, but as a legal principle whose limits are ultimately for the courts to define (Allan, 2013). While these remarks remain obiter and highly contested, they represent a significant judicial evolution, signalling a departure from subservience to an absolute Parliament towards a partnership in which the judiciary polices the fundamental tenets of the constitution.
Conclusion
In conclusion, the doctrine of parliamentary sovereignty, in its absolute Diceyan form, is no longer compatible with the prevailing principles of modern constitutionalism that have taken root in the UK. The notion of an entirely unfettered legislature stands in direct opposition to the modern emphasis on limited government, the rule of law, and the protection of fundamental rights. However, the doctrine has not been extinguished; rather, it has been substantively qualified and recalibrated. The experience of EU membership, culminating in Factortame, demonstrated that Parliament’s authority could be practically limited by a higher legal order, a lesson that has reshaped constitutional understanding despite Brexit. More enduringly, the Human Rights Act 1998 has embedded a culture of rights-based justification into the legislative process and empowered the judiciary to act as a constitutional watchdog, albeit in a manner that preserves Parliament’s final say. Finally, the judicial reasoning in cases like Jackson signals a deeper shift, suggesting that sovereignty itself is grounded in, and limited by, more fundamental principles such as the rule of law. The UK constitution now exists in a state of dynamic tension, where the democratic legitimacy of Parliament coexists with legal and political constraints that align it more closely with the ideals of modern constitutionalism. As such, parliamentary sovereignty survives, but not as the absolute monarch Dicey described; it is now a constitutional principle conditioned by, and in dialogue with, the other pillars of a modern democratic state.
References
- Allan, T.R.S. (2013) ‘The Rule of Law and the Independence of the Judiciary’, in: The Sovereignty of Law: Freedom, Constitution and Common Law. Oxford: Oxford University Press.
- Bingham, T. (2010) The Rule of Law. London: Allen Lane.
- Dicey, A.V. (1915) Introduction to the Study of the Law of the Constitution. 8th ed. London: Macmillan.
- Elliott, M. (2011) The Constitutional Foundations of Judicial Review. Oxford: Hart Publishing.
- Wade, H.W.R. (1996) ‘Sovereignty—Revolution or Evolution?’, Law Quarterly Review, 112, pp. 568-577.
Case Law
- A v Secretary of State for the Home Department [2004] UKHL 56
- Ghaidan v Godin-Mendoza [2004] 2 AC 557
- Pickin v British Railways Board [1974] AC 765
- R (Jackson) v Attorney General [2005] UKHL 56
- R v Secretary of State for Transport, ex parte Factortame Ltd (No 2) [1991] 1 AC 603
Legislation
- Bill of Rights 1689
- European Communities Act 1972
- Human Rights Act 1998
- European Union (Withdrawal) Act 2018
