Authored By: Vinutna Eathakota
De Montfort University
Parliamentary Supremacy has been considered the foundational principle of the United Kingdom’s Constitutional system. However, modern developments, like judicial decisions involving European Union law, Human Rights, and constitutional principles, have raised questions about whether Parliamentary supremacy continues to function in its traditional form.[1] This essay will therefore examine the doctrine, analyzing the major judicial developments affecting it, and evaluates whether these changes modified how parliamentary sovereignty works in practice.
The classic definition of Parliamentary sovereignty was defined by A.V. Dicey during the nineteenth century.[2] Dicey argued that Parliament has the legal authority to make or unmake any law, that no Parliament can bind its successors, and that no court or body can strike down an Act of Parliament.[3] Under the traditional view, Parliament is considered the highest legal authority within the UK constitutional system.[4] Possessing the power to enact or repeal any law, not being bound by previous Parliaments, and with its legislation not subject to invalidation by the Courts which are legally required to apply Acts of Parliament.[5] Therefore, Parliamentary supremacy is justified on democratic grounds, as it ensures that elected representatives remain the ultimate law-making authority.[6] Historically, the courts have strongly protected this principle, as shown in Madzimbamuto v Lardner-Burke [1969].[7] Lord Reid’s judgment, confirmed that the judiciary cannot override Acts of the Parliament, although judges play an important role in shaping the law through interpretation, accordingly, even where legislation appears to conflict with international law or constitutional principles, the courts will interpret rather than invalidate primary legislation, supporting the orthodox view of parliamentary sovereignty. This case serves as the primary evidence in my analysis to prove that Parliament’s law-making power is sovereign and cannot be legally challenged by the courts.[8] Another element of orthodox Parliamentary sovereignty was the doctrine of implied repeal. If two Acts of Parliament conflict, the later Act automatically overrides the earlier one, without the need for the earlier Act to be expressly repealed.[9] This principle was confirmed in Vauxhall Estates Ltd v Liverpool Corporation and Ellen Street Estates v Minister of Health.[10] Although the traditional doctrine suggests that Parliamentary power is sovereign, scholars like TRS Allan argues for considering the Rule of Law, suggesting potential moral limits on legislative competence.[11] Furthermore, as Bogdanor highlights, the UK’s lack of a codified constitution means the judiciary lacks the authority to invalidate Acts of Parliament.[12] This ensures that sovereignty remains absolute, an argument supported by Bradley, Ewing, and Knight, who argue that the UK system permits no ‘higher law’ to limit legislative power.[13] The most significant challenge to orthodox parliamentary sovereignty arose from the United Kingdom’s membership of the European Union.[14] The European Communities Act 1972 incorporated European Community law into domestic law and required domestic courts to give effect to directly effective provision of European law.[15] This created constitutional tension because EU law operated on the principle of supremacy over conflicting national legislation.[16] The issue became particularly evident in R v Secretary of State for Transport, ex parte Factortame Ltd.[17] Spanish fishermen challenged provisions of the Merchant Shipping Act 1988 on the basis that they were incompatible with European law.[18] The House of Lords consequently suspended the operation of the relevant provisions and gave priority to EU law.[19]
The constitutional significance of Factortame was unprecedented, as it marked the first time a domestic court effectively disapplied an Act of Parliament.[20] Traditionally, courts did not have this power, but the judiciary accepted that the ECA 1972 imposed an obligation to give priority to European law.[21] As Sir William Wade famously argued, this represented a constitutional revolution that modified the traditional rule of judicial obedience to accommodate EU obligations.[22] Many constitutional scholars view Factortame as a direct limitation upon Parliamentary sovereignty.[23] If courts were capable of declining to apply an Act of Parliament, the doctrine of Legislative supremacy could no longer be regarded as entirely sovereign.[24] On the other hand, scholars such as Jeffrey Goldsworthy contend that Parliamentary sovereignty formally survived during the EU period because the supremacy of European law derived from Parliament’s voluntary acceptance through the ECA Act 1972.[25] According to his view, sovereignty was not abolished but temporarily limited through Parliament’s own decision.[26] The enactment of the European Union (Withdrawal) Act 2018 is widely seen as supporting this argument, demonstrating that Parliament ultimately retained the legal authority to restore its complete legislative independence.[27] Thus, although the formal doctrine of Parliamentary sovereignty remained intact during the EU period, the decision in Factortame unquestionably altered constitutional practice within the United Kingdom. As noted by A. W. Bradley, K. D. Ewing, and Christopher Knight, Parliament’s legislative freedom became subject to external constraints previously unknown within the constitutional framework.[28] Furthermore, Paul Craig argues that this period marked a major shift in the judiciary’s constitutional role, with courts moving beyond a purely passive function toward a more active role in defining constitutional boundaries, thereby altering the traditional balance of power.[29]
Another major constitutional development was the Human Rights Act 1998.[30] The Act incorporated the ECHR into domestic law and significantly increased the judiciary’s constitutional influence over legislation.[31] Beyond the influence of the EU, the Human Rights Act 1998 introduced a domestic mechanism for protecting rights, further nuancing the traditional doctrine.[32] As Francesca Klug argues, this created a ‘new bill of rights’ designed to coexist with Parliamentary supremacy.[33] However, this constitutional shift was not without controversy; scholars like K. D. Ewing have raised concerns that such powers could potentially weaken Parliamentary democracy by shifting too much authority toward the judiciary.[34] A leading example is Ghaiden v Godin-Mendoza.[35] The House of Lords interpreted provisions of the Rent Act 1977 as permitting same-sex partners to inherit statutory tenancies despite the wording appearing to restrict such rights.[36] The decision illustrated the judiciary’s willingness to interpret legislation broadly in order to ensure consistency with human rights principles. The Human Rights Act 1998 also introduced a declaration of incompatibility under section 4, enabling courts to declare that legislation conflicts with Convention rights without invalidating the legislation itself.[37] This preserves formal Parliamentary Sovereignty, although such declarations often place political pressure on Parliament to amend the law.[38] Critics argue that the Act grants excessive influence to the judiciary, particularly through section 3 interpretations that may effectively alter the meaning of legislation. Supporters, however, contend that the Act promotes a constitutional dialogue between courts and Parliament while protecting fundamental rights. Although courts still cannot strike down Acts of Parliament, the Act has strengthened judicial constitutional review and modified the practical operation of Parliamentary Sovereignty.
A further judicial development arose in Thoburn v Sunderland City Council, commonly known as the “Metric Martyrs” case.[39] In this case, Lord Justice Laws introduced the concept of constitutional statutes.[40] He explained that certain statutes are constitutional because they affect fundamental constitutional rights or the relationship between citizens and the state.[41] Examples include the Magna Carta, the Human Rights Act 1998, and the European Communities Act 1972.[42] Importantly, such constitutional statutes are not subject to implied repeal.[43] Instead, Parliament must expressly repeal them with clear, unequivocal wording.[44] The constitutional debate developed further in Jackson v Attorney General.[45] While the court ultimately upheld the legislation, the comments of Lord Steyn and Lord Hope challenged the orthodox view by suggesting that Parliamentary sovereignty is a ‘construct of the common law’ rather than an absolute, untouchable fact. Although these remarks were made obiter dicta, they reflect an increasing judicial willingness to treat the Rule of Law as the ‘ultimate controlling factor’ within the Constitution.
Brexit-related litigation further illustrated the judiciary’s increasingly assertive constitutional role. In R (Miller) v Secretary of State for Exiting the European Union, the Supreme Court held that the government could not invoke Article 50 without prior Parliamentary approval, since withdrawal from the European Union would affect domestic legal rights created by Parliament.[46] The judgment reinforced Parliamentary sovereignty by confirming that ministers could not bypass Parliament when introducing major constitutional changes.[47] However, it demonstrated the judiciary’s willingness to intervene in politically sensitive constitutional matters.[48] A more controversial decision later arose in R (Miller) v Prime Minister, concerning the Prime Minister’s advice to prorogue Parliament during the Brexit crisis.[49] The Supreme Court unanimously held that the prorogation was unlawful because it prevented Parliament from performing its constitutional functions without reasonable justification.[50] Although neither of the Miller cases involved striking down legislation, both decisions illustrated the judiciary’s increasingly active role in protecting constitutional principles, particularly the Rule of Law and Parliamentary accountability.[51]
Recent Judicial developments have significantly changed how Parliamentary sovereignty works in practice.[52] Courts now exercise a greater constitutional role through the interpretation of Human Rights, recognition of Constitutional statutes, and Judicial Review of executive action.[53] Nevertheless, Parliamentary Sovereignty has not been formally displaced.[54] Parliament remains legally competent to enact legislation contrary to constitutional principles, expressly repeal constitutional statutes, and override judicial decisions through legislation. Unlike constitutional courts in jurisdictions such as the United States, UK courts continue to lack a general power to invalidate Acts of Parliament. However, the constitution has moved beyond Dicey’s traditional orthodox model. Parliamentary sovereignty no longer functions in isolation but operates alongside wider constitutional principles, including the Rule of Law, Judicial Review, Human Rights Protection, and constitutional accountability. Consequently, recent Judicial decisions have not abolished legislative supremacy, but have significantly modified its operation in practice. The modern UK constitution therefore, reflects a more balanced constitutional relationship between Parliament and the Judiciary than the absolute supremacy originally envisaged by Dicey.
Bibliography
Table of Cases
Ellen Street Estates v Minister of Health [1934] 1 KB 590
Ghaiden v Godin-Mendoza [2004] UKHL 30, [2004] 2 AC 557
Jackson v Attorney General [2005] UKHL 30, [2006] 1 AC 262
Madzimbamuto v Lardner-Burke [1969] 1 AC 645
R (Miller) v Prime Minister [2019] UKSC 41, [2020] AC 373
R (Miller) v Secretary of State for Exiting the European Union [2017] UKSC 5 [2018] AC 61
R v Secretary of State for Transport, ex parte Factortame Ltd (No 2) [1991] 1 AC 603
Thoburn v Sunderland City Council [2002] EWHC 195 (Admin), [2003] QB 151
Vauxhall Estates Ltd v Liverpool Corporation [1932] 1 KB 733
Table of Legislation
Consumer Rights Act 2015
European Communities Act 1972
European Union (Withdrawal) Act 2018
Human Rights Act 1998
Merchant Shipping Act 1988
Rent Act 1977
Unfair Contract Terms Act 1977
Secondary Sources
Books
Allan TRS, Law, Liberty, and Justice: The Legal Foundations of the British Constitution (Oxford University Press, 1993)
Bradley AW, Ewing KD, and Knight C, Constitutional and Administrative Law (18th edn, Pearson 2022)
Dicey AV, Introduction to the Study of the Law of the Constitution (10th edn, Macmillan 1959)
Goldsworthy J, The Sovereignty of Parliament: History and Philosophy (Clarendon Press 1999)
Journal Articles
Craig P, ‘Sovereignty after the Human Rights Act’ (1998) 114 Law Quarterly Review 57
Ewing KD, ‘The Futility of the Human Rights Act’ [2004] Public Law 829
Klug F, ‘The Human Rights Act – A “Third Way” or “Third Wave” Bill of Rights’ [2001] Public Law 361
Wade HWR, ‘The Basis of Legal Sovereignty’ [1955] Cambridge Law Journal 172
[1] Alison L Young, Parliamentary Sovereignty and the Human Rights Act (Hart Publishing 2009) 1-3
[2] A. V. Dicey, Introduction to the Study of the Law of the Constitution (10th edn, Macmillan 1959) 39
[3] Ibid 39-40
[4] Jeffrey Goldsworthy, The Sovereignty of Parliament: History and Philosophy (Oxford University Press, 1999) 1-3
[5] Mark Elliott and Robert Thomas, Public Law (4th edn, Oxford University Press 2023) 60
[6] ibid
[7] Madzimbamuto v Lardner-Burke [1969] 1 AC 645 (PC) 723 (Lord Reid)
[8] Sir William Wade and Christopher Forsyth, Administrative Law (11th edn, Oxford University Press 2014) 24-25
[9] Elliott and Thomas (n 3) 63-64
[10] Vauxhall Estates Ltd v Liverpool Corporation [1932] 1 KB 733; Ellen Street Estates v Minister of Health [1934] 1 KB 590
[11] TRS Allan, Constitutional Justice: A Liberal Theory of the Rule of Law (Oxford University Press, 2001)
15-17
[12] Vernon Bogdanor, The New British Constitution (Hart Publishing 2009) 63-65
[13] Bradley, Ewing & Knight, Constitutional and Administrative Law (17th edn, Pearson 2018) 58-60
[14] ibid
[15] European Communities Act 1972, s 2(1)
[16] Paul Craig, UK, EU and Global Administrative Law (Cambridge University Press 2015) 102
[17] R v Secretary of State for Transport, ex parte Factortame Ltd [1991] 1 AC 603
[18] Mark Elliott and Robert Thomas, Public Law (4th edn, Oxford University Press 2023) 60
[19] Factortame (n 4) 658-659
[20] ibid
[21] A. V. Dicey, Introduction to the Study of the Law of the Constitution (10th edn, Macmillan 1959) 39-40
[22] Sir William Wade, ‘Sovereignty-Revolution or Evolution?’ (1996) 112 LQR 568, 573
[23] Wade (n 9) 574
[24] Alison L Young, Parliamentary Sovereignty and the Human Rights Act (Hart Publishing 2009) 25
[25] Jeffrey Goldsworthy, Parliamentary Sovereignty: Contemporary Debates (Cambridge University Press 2010) 269
[26] Goldsworthy (n 12) 270
[27] European Union (Withdrawal) Act 2018, s 1
[28] ibid
[29] Paul Craig, ‘Sovereignty of the United Kingdom Parliament after Factortame’ (1991) 11 Yearbook of European Law 221, 236
[30] Human Rights Act 1998
[31] ibid
[32] Human Rights Act 1998, s 3(1)
[33] Francesca Klug, Values for a Godless Age: The Story of the United Kingdom’s New Bill of Rights (Penguin 2000) 117; Mark Elliott and Robert Thomas, Public Law (4th edn, Oxford University Press 2023) 407
[34] K D Ewing, ‘The Human Rights Act and Parliamentary Democracy’ (1999) 62 MLR 79, 88
[35] Ghaidan v Godin- Mendoza [2004] UKHL 30, [2004] 2 AC 557
[36] Ghaidan (n 5) [33]-[34] (Lord Nicholls)
[37] Human Rights Act 1998, s 4
[38] ibid
[39] Thoburn v Sunderland City Council [2002] EWHC 195 (Admin), [2003] QB 151
[40] Thoburn (n 1) [62] (Laws LJ)
[41] Mark Elliot, ‘Constitutional Legislation and Constitutional Statutes’ (2004) 120 LQR 96, 98
[42] Thoburn (n 1) [63]; Elliot and Thomas, Public Law (4th edn, Oxford University Press 2023) 66
[43] ibid
[44] Bradley, Ewing and Knight, Constitutional and Administrative Law (17th edn, Pearson 2018) 61
[45] Jackson v Attorney General [2005] UKHL 56, [2006] 1 AC 262
[46] R (Miller) v Secretary of State for Exiting the European Union [2017] UKSC 5, [2018] AC 61 [82]-[83]
[47] ibid
[48] ibid
[49] R (Miller) v Prime Minister [2019] UKSC 41, [2020] AC 373
[50] Miller (No 2) (n 3) [50]-[52]
[51] Vernon Bogdanor, Beyond Brexit: Towards a British Constitution (IB Tauris 2019) 102: TRS Allan, Constitutional Justice: A Liberal Theory of the Rule of Law (Oxford University Press 2001) 287
[52] idib
[53] Alison L Young, Parliamentary Sovereignty and the Human Rights Act (Hart Publishing 2009) 84
[54] Jeffrey Goldsworthy, Parliamentary Sovereignty: Contemporary Debates (Cambridge University Press, 2010) 281
