Introduction
A constitution is a set of fundamental principles or established precedents according to which a state is governed. In many legal systems, the constitution is regarded as the supreme law of the land, meaning all other laws and governmental actions must comply with its provisions. This essay will explain the reasons for this supremacy by first examining the role of codified constitutions. It will then contrast this with the traditional UK position of parliamentary sovereignty, before considering how modern developments have created a more complex picture in the UK, where the idea of constitutional supremacy is becoming more relevant.
The Basis of Constitutional Supremacy
In countries with a codified, written constitution, such as the United States, the constitution’s supremacy is a foundational principle. The constitution is supreme for several key reasons. Firstly, it is the originating source of state authority. It creates the main institutions of government—the legislature, the executive, and the judiciary—and defines the scope of their powers. As the document that gives these bodies their legal existence, it logically stands above them in the legal hierarchy.
Secondly, the constitution places limits on state power to protect citizens. This is often achieved through a Bill of Rights, which guarantees fundamental freedoms that the government cannot infringe upon. The US Supreme Court case of Marbury v Madison (1803) established the principle of judicial review, empowering courts to strike down laws passed by the legislature if they are found to be unconstitutional. This demonstrates that the constitution acts as a higher law. Finally, constitutions are typically ‘entrenched’, meaning they are deliberately difficult to amend, requiring special procedures beyond a simple majority vote in the legislature. This entrenchment reinforces their status as a superior and more permanent form of law compared to ordinary legislation.
The UK's Uncodified Constitution and Parliamentary Sovereignty
The position in the United Kingdom is traditionally different. The UK has an uncodified constitution, derived from various sources including statutes, case law, and constitutional conventions. In this system, the dominant principle has not been constitutional supremacy, but rather the sovereignty of Parliament. As famously outlined by A.V. Dicey, this doctrine has three main elements: Parliament can make or unmake any law whatsoever; no Parliament can bind a future Parliament; and no court can question the validity of an Act of Parliament (Dicey, 1915).
Under this traditional view, the ultimate source of legal authority is not the constitution, but the most recent expression of Parliament’s will. An Act of Parliament is the highest form of law, and courts must enforce it, as affirmed in cases like British Railways Board v Pickin [1974] AC 765. Therefore, in theory, Parliament could legislate contrary to fundamental constitutional principles, and the courts would be powerless to invalidate that legislation. In this sense, Parliament, not the constitution, has been considered supreme.
Modern Challenges and a Shift in Thinking
However, the absolute nature of parliamentary sovereignty has been challenged in recent decades. The UK’s membership of the European Union (from 1973 to 2020) had a significant impact. The European Communities Act 1972 required UK courts to give precedence to EU law over conflicting national legislation. In R (Factortame Ltd) v Secretary of State for Transport (No 2) [1991] 1 AC 603, the House of Lords did something unprecedented: it suspended the application of an Act of Parliament because it conflicted with EU law. This demonstrated that parliamentary sovereignty was not absolute and could be limited by statute.
Furthermore, the Human Rights Act 1998 (HRA) incorporates the European Convention on Human Rights into UK domestic law. Under section 3 of the HRA, courts must, so far as possible, interpret legislation in a way that is compatible with Convention rights. If this is not possible, a higher court can issue a 'declaration of incompatibility' under section 4. While this does not invalidate the law, it puts significant political pressure on Parliament to amend it. These developments, along with judicial suggestions in cases like Jackson v Attorney General [2005] UKHL 56 that the rule of law may ultimately be the controlling principle in the constitution, suggest a move away from pure parliamentary supremacy towards a system where certain principles and rights have a higher, quasi-constitutional status.
Conclusion
In conclusion, a constitution is typically considered the supreme law because it is the source of all state power and sets legally enforceable limits upon it, particularly in systems with a codified document. While the UK has historically operated under the opposing doctrine of parliamentary sovereignty, this principle is no longer as absolute as it once was. The impact of the European Communities Act 1972 and the Human Rights Act 1998 has demonstrated that Parliament can be subject to higher legal norms. Therefore, while the UK has not formally adopted constitutional supremacy in the way the US has, its legal system now contains significant elements that reflect the idea of a supreme constitutional order, where even Acts of Parliament are measured against fundamental principles and rights.
References
- Dicey, A.V. (1915) Introduction to the Study of the Law of the Constitution. 8th edn. Macmillan.
- British Railways Board v Pickin [1974] AC 765.
- Jackson v Attorney General [2005] UKHL 56.
- Marbury v Madison, 5 U.S. 137 (1803).
- R (Factortame Ltd) v Secretary of State for Transport (No 2) [1991] 1 AC 603.
