Introduction
Parliamentary supremacy, often considered the cornerstone of the United Kingdom’s unwritten constitution, asserts that Parliament is the supreme legal authority, capable of making or repealing any law without being challenged by other institutions. However, the UK’s integration into the European Union (EU) from 1973 to 2020 introduced significant challenges to this principle, as EU law often demanded precedence over domestic legislation. This essay explores how EU law has contested parliamentary supremacy, with specific reference to A.V. Dicey’s orthodox theory of parliamentary sovereignty. It also considers alternative perspectives, such as those of Lord Denning and academic critiques, to provide a rounded analysis. The discussion will focus on key legal developments, including the European Communities Act 1972 and landmark judicial decisions, to illustrate the tension between EU law and parliamentary authority.
Dicey’s Orthodox Theory of Parliamentary Supremacy
A.V. Dicey, a prominent constitutional scholar, articulated the orthodox view of parliamentary supremacy in his seminal work, *An Introduction to the Study of the Law of the Constitution* (1885). Dicey argued that Parliament holds absolute legislative authority, meaning it can enact or repeal any law, and no body, including the courts, can question its validity (Dicey, 1885). Furthermore, he posited that no Parliament can bind its successors, ensuring that future Parliaments remain free to alter or undo previous legislation. This theory has long served as the bedrock of the UK’s constitutional framework, reinforcing the idea that parliamentary will is paramount.
However, Dicey’s theory assumes a purely domestic legal order, unencumbered by external influences. The integration of EU law into the UK system, following the enactment of the European Communities Act 1972, introduced a competing legal framework that arguably undermined Dicey’s vision. EU law, with its principles of direct effect and supremacy, required UK courts to prioritise European legislation over conflicting domestic law—a direct challenge to the notion that Parliament is unfettered by external constraints.
The Impact of EU Law on Parliamentary Supremacy
The European Communities Act 1972 (ECA 1972) marked a pivotal moment in the relationship between UK and EU law. Section 2(1) of the ECA 1972 incorporated EU law into the domestic legal system, granting it direct effect, meaning that certain EU provisions could be enforced by individuals in UK courts without additional domestic legislation (Loveland, 2018). Additionally, Section 2(4) implied that UK legislation must be interpreted in conformity with EU law, even if this required courts to set aside inconsistent domestic statutes. This statutory framework suggested that Parliament had voluntarily limited its own sovereignty—a notion that sits uncomfortably with Dicey’s assertion that no Parliament can bind its successors.
The principle of the supremacy of EU law, established by the European Court of Justice (ECJ) in cases such as Costa v ENEL (1964), further intensified this challenge. The ECJ ruled that EU law takes precedence over national law, even where national legislation predates or conflicts with EU provisions. In the UK context, this principle was most starkly illustrated in the landmark case of R v Secretary of State for Transport, ex parte Factortame Ltd (No 2) (1991). Here, the House of Lords accepted that UK courts must disapply domestic legislation—specifically, provisions of the Merchant Shipping Act 1988—that conflicted with EU law protecting freedom of establishment. This decision was unprecedented, as it demonstrated that parliamentary legislation could be sidelined by judicial decision, directly contradicting Dicey’s view that courts cannot question parliamentary enactments (Craig, 2011).
Judicial and Academic Perspectives on the Challenge
Beyond Dicey’s orthodox theory, other perspectives shed light on the evolving nature of parliamentary supremacy in light of EU law. Lord Denning, a prominent judicial figure, offered a pragmatic view in *Macarthys Ltd v Smith* (1979), where he acknowledged that EU law, by virtue of the ECA 1972, had altered the traditional understanding of sovereignty. Denning famously remarked that if Parliament were to pass legislation contrary to EU law, UK courts would be bound to give effect to EU provisions—a position that suggests a de facto limitation on parliamentary authority, even if parliamentary supremacy remains theoretically intact (Barnett, 2017).
Academic critiques have further nuanced this debate. For instance, Loveland (2018) argues that the UK’s membership in the EU represented a form of ‘pooled sovereignty,’ where Parliament voluntarily ceded certain legislative powers to EU institutions. This perspective implies that parliamentary supremacy was not wholly eroded but rather adapted to accommodate international commitments. Conversely, some scholars, such as Wade (1996), contend that the judicial acceptance of EU law’s supremacy fundamentally altered the constitutional landscape, rendering Dicey’s theory obsolete during the period of EU membership. Wade’s assertion hinges on the idea that the ECA 1972 created a new constitutional reality, where courts could override parliamentary legislation—a development Dicey could not have foreseen.
Post-Brexit Implications and Continuing Tensions
Although the UK officially left the EU on 31 January 2020, the legacy of EU law continues to challenge parliamentary supremacy. The European Union (Withdrawal) Act 2018 retained much of EU-derived legislation as ‘retained EU law’ in the domestic system, albeit with the proviso that Parliament can amend or repeal such laws. However, during the transition period and beyond, UK courts have grappled with the status of pre-existing EU case law, particularly ECJ rulings. The tension between restoring full parliamentary sovereignty and respecting retained EU legal principles suggests that Dicey’s vision of absolute legislative authority remains elusive in a post-Brexit context (Elliott, 2020).
Moreover, the Brexit process itself reaffirmed the theoretical resilience of parliamentary supremacy. The UK’s withdrawal from the EU was ultimately enacted through parliamentary legislation, demonstrating that Parliament retained the power to disentangle itself from external legal obligations. This arguably aligns with Dicey’s principle that no Parliament is bound by its predecessors, as the repeal of the ECA 1972 illustrated Parliament’s ability to reclaim sovereignty (Craig, 2011). Nevertheless, the practical challenges of unwinding decades of legal integration highlight the enduring influence of EU law on the UK’s constitutional framework.
Conclusion
In conclusion, EU law has posed a significant challenge to parliamentary supremacy, particularly by requiring UK courts to prioritise European provisions over domestic legislation, as seen in cases like *Factortame*. This development directly conflicts with Dicey’s orthodox theory, which holds that Parliament is the ultimate legal authority and cannot be bound by external constraints. Perspectives from figures like Lord Denning and academics such as Loveland and Wade further illuminate the tension, suggesting that parliamentary sovereignty has either been adapted or fundamentally altered by EU integration. Even post-Brexit, the legacy of EU law continues to complicate the restoration of Dicey’s vision of absolute sovereignty. Ultimately, the interaction between EU law and parliamentary supremacy underscores the evolving nature of the UK’s constitution, highlighting the difficulty of maintaining traditional principles in an increasingly interconnected legal landscape. This ongoing debate invites further reflection on whether parliamentary supremacy can remain a viable doctrine in the face of international obligations.
References
- Barnett, H. (2017) Constitutional & Administrative Law. 12th edn. Routledge.
- Craig, P. (2011) UK, EU and Global Administrative Law: Foundations and Challenges. Cambridge University Press.
- Dicey, A.V. (1885) An Introduction to the Study of the Law of the Constitution. Macmillan.
- Elliott, M. (2020) Brexit and the Future of the UK Constitution. Oxford University Press.
- Loveland, I. (2018) Constitutional Law, Administrative Law, and Human Rights: A Critical Introduction. 8th edn. Oxford University Press.
- Wade, H.W.R. (1996) ‘Sovereignty – Revolution or Evolution?’ Law Quarterly Review, 112, pp. 568-575.
