Is the United Kingdom Parliament Still Sovereign?
- Parliamentary sovereignty means UK courts have no power to overturn legislation, unlike the U.S.’s judicial review.
- This principle is at odds with the EU’s system.
- The Factortame case forced the reconciliation of the EU and UK system.
This article is by David Schmidt, a 2L from Chicago-Kent who is currently attending law school in London.
A core principle of the United Kingdom’s (UK) uncodified constitution is the principle of parliamentary sovereignty. The authority on this principle is law professor A.V. Dicey in his 1885 treatise, An Introduction to the Study of the Law of the Constitution, where he writes that the UK parliament has “the right to make or unmake any law whatever; and, further, that no person or body is recognized by the law of England as having a right to override or set aside the legislation of Parliament.” Thus, parliamentary sovereignty means that the courts of the UK have no power to overturn legislation, in stark contrast to the United States’ principle of judicial review.
This principle of parliamentary sovereignty is now at odds with the UK’s current role as a member state in the European Union (EU), subject to the supremacy of European law. Unlike the United States constitution, which contains a supremacy clause, the EU’s constitutional treaties contain no supremacy clause, either in their original form as the 1957 Treaty of Rome, or in their current form as the Treaty on European Union (TEU), and the Treaty on the Functioning of the European Union (TFEU). Much like the United States Supreme Court’s decision to create the principle of judicial review in Marbury v. Madison, the European Court of Justice (ECJ) took it upon itself to declare EU law supreme. In the 1964 case, Costa v. ENEL, the ECJ declared that EU treaties, legislation, and caselaw are the supreme law of the land, and that the national courts of member states are bound to misapply laws of the member states that are in conflict with Union law. This principle of EU supremacy is in direct contradiction with parliamentary sovereignty, which expressly prohibits UK courts from disapplying acts of parliament.
The Factortame cases are a series of litigation in the 1990s over the compatibility of the UK’s Merchant Shipping Act of 1988 and EU law. In Factortame, the ECJ held that the UK courts must set aside the Merchant Shipping Act because it was in conflict with EU law. After this decision, the UK courts had the choice to adhere to parliamentary sovereignty and uphold the Shipping Act, or adhere to EU supremacy and set aside the act. With parliamentary sovereignty and EU supremacy at odds, the UK courts needed to reconcile this paradoxical situation.
When Factortame returned to the House of Lords, the court issued an injunction to suspend the Merchant Shipping Act of 1988. It explained that by setting aside the law, the court was in fact enforcing the will of parliament, not usurping parliamentary sovereignty. 
The UK had entered the EU in 1973 when it passed the European Communities Act of 1972. In this act, parliament declared that the UK courts must interpret English law in accordance with EU law; effectively limiting parliament’s sovereignty. If the 1988 Shipping Act was incompatible with EU law, it would also be in conflict with the European Communities Act of 1972. Although the last in time principle generally applies when two statutes of parliament are in conflict, the House of Lords explained that the 1972 act was a special constitutional statute which could not be overturned by subsequent legislation, such as the Merchant Shipping Act, without an express statement by parliament that it was overturning the previous constitutional statute. In this way, by invalidating the Merchant Shipping Act of 1988, the House of Lords was enforcing the will of the 1972 parliament to voluntarily limit its sovereignty, thus upholding the principle of parliamentary sovereignty and adhering to the principle of EU supremacy.
Although the Factortame cases legally preserve UK parliamentary sovereignty by holding that parliament can expressly repeal the European Communities Act and withdraw from the EU, it is politically and practically unlikely. For the foreseeable future, the United Kingdom will remain a member state of a federal system, thus provoking debate over whether its parliament is truly still sovereign.
 A.V. Dicey, An Introduction to the Study of the Law of the Constitution (Macmillan, 8th ed. 1996) at 38.
 See Case 6/64, Costa v. ENEL,  E.C.R. 585, 593-94 (1964).
 See R v Secretary of State for Transport, ex p. Factortame Ltd (No.2)  EUECJ C-213/89 (19 June 1990).
 See R v Secretary of State for Transport ex p Factortame Ltd (Interim Relief Order)  UKHL 7 (26 July 1990).