Supreme Court Affirms Parliamentary Authority Over the Protocol on Ireland/Northern Ireland

Introduction

The case Allister & Peeples, Re Applications for Judicial Reviews (Northern Ireland) ([2023] UKSC 5) revolved around the lawfulness of the Protocol on Ireland/Northern Ireland ("the Protocol"). This Protocol forms part of the Withdrawal Agreement between the United Kingdom ("the UK") and the European Union ("the EU") under Article 50(2) of the Treaty on European Union (TEU), outlining the arrangements for the UK's withdrawal from the EU.

The appellants, comprising James Hugh Allister, Benyamin Naeem Habib, Baroness Catharine Hoey of Lylehill and Rathlin, Steve Aiken, the Rt Hon Arlene Isobel Foster, and the Rt Hon Baron Trimble of Lisnagarvey, challenged the lawfulness of the Protocol. Their primary contention was that the Protocol conflicted with constitutional provisions, specifically Article VI of the Acts of Union 1800 and Section 1 of the Northern Ireland Act 1998 (NIA 1998). Additionally, they disputed the legitimacy of the 2020 Regulations altering cross-community voting mechanisms in the Northern Ireland Assembly.

After successive dismissals in the lower courts, the appellants sought a review from the Supreme Court, raising significant questions about parliamentary sovereignty, constitutional law, and the interplay between domestic statutes and international agreements.

Summary of the Judgment

The United Kingdom Supreme Court dismissed all grounds of appeal brought forward by the appellants. Lord Stephens, delivering the judgment agreed upon by Lords Reed, Hodge, Lloyd-Jones, and Sales, concluded that the Protocol on Ireland/Northern Ireland does not unlawfully override or conflict with the Acts of Union 1800 or the NIA 1998. The court emphasized the supremacy of Parliament and its authority to modify existing statutes, including constitutional ones.

Specifically:

• Ground One: The appellants argued that the Protocol conflicted with Article VI of the Acts of Union 1800. The court held that Parliament, through the European Union (Withdrawal) Act 2018 and subsequent legislation, rightfully modified Article VI to incorporate the Protocol.
• Ground Two: The contention was that the Protocol altered the constitutional status of Northern Ireland without a democratic mandate as required by Section 1 of the NIA 1998. The Supreme Court upheld the decision in Miller No. 1, affirming that Section 1 does not govern matters beyond the UK's withdrawal from the EU.
• Ground Three: The legality of the 2020 Regulations, which modified the cross-community voting mechanism in the Northern Ireland Assembly, was challenged. The court found these regulations to be lawful extensions of Parliament's authority, ensuring compatibility with the NIA 1998 as amended.

Ultimately, the Supreme Court underscored the principle of parliamentary sovereignty, affirming that Parliament possesses the ultimate legal authority to enact, modify, or repeal any statute, including those of constitutional significance.

Analysis

Precedents Cited

The judgment extensively referenced Miller No. 1 (R (Miller) v Secretary of State for Exiting the European Union [2017] UKSC 5), a landmark case that established the necessity of parliamentary approval for triggering Article 50 TEU. In Miller No. 1, the Supreme Court affirmed that the government could not unilaterally trigger Brexit without an Act of Parliament, emphasizing the constraints on the prerogative powers by statutory provisions.

Additionally, the court invoked principles from Thoburn v Sunderland City Council [2002] EWHC 195 (Admin); [2003] QB 151, which introduced the "Metric Martyrs" concept, distinguishing between ordinary statutes and constitutional statutes that require explicit legislative action for any modification. This distinction was pivotal in assessing whether the Acts of Union could be implicitly or explicitly modified by subsequent legislation.

Legal Reasoning

The crux of the Supreme Court's reasoning rested on the indivisible nature of parliamentary sovereignty. The court posited that Parliament, as the supreme legal authority in the UK, holds the power to enact, modify, or repeal any statute, irrespective of its constitutional significance.

Ground One: The appellants argued that the Protocol infringed upon the rights enshrined in Article VI of the Acts of Union 1800, which guarantees equal trade privileges between Great Britain and Ireland. The court determined that Parliament, through the European Union (Withdrawal) Act 2018 and the European Union (Withdrawal Agreement) Act 2020, explicitly legislated to incorporate the Withdrawal Agreement and the Protocol into domestic law. This legislative action effectively modified Article VI, reflecting Parliament's sovereign will to adapt existing laws in response to new international agreements.

Ground Two: The appellants contended that the Protocol altered Northern Ireland's constitutional status without securing a democratic mandate as prescribed by Section 1 of the NIA 1998. The court revisited the ruling in Miller No. 1, reinforcing the stance that Section 1 does not extend beyond determining Northern Ireland's union status vis-à-vis a united Ireland. Consequently, the Protocol's impact on trade does not constitute a change in constitutional status requiring a referendum.

Ground Three: The legality of the 2020 Regulations, which allowed for simple majority votes on certain Protocol provisions within the Northern Ireland Assembly, was challenged. The court upheld these regulations, citing the clear legislative authority granted by Section 8C of the European Union (Withdrawal) Act 2018. The court rejected the appellants' "Henry VIII" challenge, emphasizing that the enabling statute unambiguously permitted such modifications to primary legislation.

Impact

This judgment reinforces the principle of parliamentary sovereignty, affirming that Parliament retains the ultimate authority to navigate and modify constitutional landscapes in response to international agreements. The decision ensures that the Protocol on Ireland/Northern Ireland remains a lawful component of UK law, provided it aligns with the legislative framework established by Parliament.

For future cases, this ruling sets a precedent that constitutional statutes can be modified or overridden by subsequent legislation, provided such actions are within the clear intent of Parliament. It also delineates the boundaries of prerogative powers, underscoring that they operate within the constraints imposed by statutory law.

Moreover, the affirmation of the 2020 Regulations' legality has significant implications for the governance of Northern Ireland, particularly in how democratic consent processes are structured in relation to EU-related agreements.

Complex Concepts Simplified

Parliamentary Sovereignty

Parliamentary sovereignty is the principle that Parliament is the supreme legal authority in the UK, capable of creating or ending any law. Generally, the courts cannot overrule its legislation and no Parliament can pass laws that future Parliaments cannot change.

Act of Parliament vs. Constitutional Statute

While all statutes passed by Parliament are laws, constitutional statutes typically pertain to the fundamental principles that govern a society. In this case, the Acts of Union 1800 and the Northern Ireland Act 1998 are considered constitutional because they address the UK's fundamental constitutional arrangements.

Prerogative Powers

Prerogative powers are the residual powers held by the Crown's executives (e.g., the Prime Minister) that allow them to manage international affairs, such as treaty-making. However, these powers can be limited or regulated by Parliament through legislation.

Judicial Review

Judicial review is a process where courts examine the lawfulness of actions or decisions made by public bodies. In this case, the appellants sought judicial review to challenge the legality of the Protocol and its implementation.

Henry VIII Clauses

These are provisions in legislation that allow ministers to amend or repeal statutes without full parliamentary scrutiny. The appellants argued that such clauses in the 2018 Act should be interpreted narrowly to prevent overreach, but the court found the enabling legislation clear in its intent.

Conclusion

The Supreme Court's decision in Allister & Peeples reaffirms the foundational legal principle of parliamentary sovereignty within the UK constitutional framework. By upholding the Protocol on Ireland/Northern Ireland and the accompanying legislative modifications, the court has delineated the extent of Parliament's authority to shape domestic law in alignment with international commitments.

This judgment underscores that while constitutional statutes hold significant weight, they remain subject to the will of Parliament. The resolution of the appellants' challenges ensures the continuity and legality of the Protocol's application, maintaining the delicate balance between national sovereignty and international obligations.

Moving forward, this ruling provides clarity on the mechanisms through which the UK can adjust its legal landscape in response to evolving political and international dynamics, reinforcing the supremacy of Parliamentary legislation in determining the nation's constitutional and legal pathways.