In the matter of an application by James Hugh Allister and others for Judicial Review [2023] UKSC 5

Northern Ireland residents challenged the lawfulness of the Protocol on Ireland/Northern Ireland, part of the Brexit Withdrawal Agreement. They argued it violated the Acts of Union 1800 and section 1 of the Northern Ireland Act 1998. The Supreme Court dismissed all appeals, holding Parliament had expressly authorised the Protocol through the 2018 and 2020 Acts.

Facts

Following the UK’s withdrawal from the EU, the Protocol on Ireland/Northern Ireland formed part of the Withdrawal Agreement. James Hugh Allister and others, along with Clifford Peeples, brought judicial review proceedings challenging the Protocol’s lawfulness. They contended that the Protocol conflicted with Article VI of the Acts of Union 1800, which provides that His Majesty’s subjects of Great Britain and Ireland shall be on the ‘same footing’ regarding trade. The Protocol created customs arrangements requiring tariffs on goods moving from Great Britain to Northern Ireland if at risk of entering the EU single market.

The Legislative Framework

The European Union (Withdrawal) Act 2018, as amended by the European Union (Withdrawal Agreement) Act 2020, incorporated the Withdrawal Agreement into domestic law through section 7A. Section 7A(3) provides that ‘every enactment (including an enactment contained in this Act) is to be read and has effect subject to’ the rights and obligations arising under the Withdrawal Agreement.

Issues

The Court of Appeal granted leave to appeal on three grounds:

1. Whether section 7A(3) of the 2018 Act lawfully modifies Article VI of the Acts of Union 1800
2. Whether the modification effects a change in constitutional status conflicting with section 1(1) of the Northern Ireland Act 1998
3. Whether the 2020 Regulations disapplying section 42 of the NIA 1998 (cross-community voting) were lawfully made

Judgment

Ground One: Article VI of the Acts of Union

Lord Stephens, delivering the unanimous judgment, held that even accepting the Protocol conflicted with Article VI, section 7A of the 2018 Act provided the complete answer:

The most fundamental rule of UK constitutional law is that Parliament, or more precisely the Crown in Parliament, is sovereign and that legislation enacted by Parliament is supreme. A clear answer has been expressly provided by Parliament in relation to any conflict between the Protocol and the rights in the trade limb of article VI.

Regarding the treaty limb of Article VI, the Court held that Parliament expressly authorised the making of the Withdrawal Agreement through the 2020 Act:

The short answer is that a sovereign Parliament by enacting the 2020 Act authorised the making of the Withdrawal Agreement (which included the Protocol).

Ground Two: Section 1 of the NIA 1998

The Court followed its earlier decision in Miller No. 1, stating:

In Miller No. 1, this court unanimously held that section 1 of the NIA 1998 does not regulate any change in the constitutional status of Northern Ireland other than the right to determine whether to remain part of the United Kingdom or to become part of a united Ireland.

Ground Three: The 2020 Regulations

The Court held that section 7A(3) had already modified section 42 of the NIA 1998 regarding the democratic consent mechanism, making the 2020 Regulations compatible with the NIA 1998 as modified.

Implications

This judgment affirms the supremacy of Parliamentary sovereignty in constitutional matters. It establishes that Parliament can, through express statutory language, modify even constitutional statutes such as the Acts of Union 1800. The decision confirms that section 1 of the NIA 1998 solely regulates whether Northern Ireland remains part of the UK or joins a united Ireland, not other constitutional changes. The judgment provides important clarification on the relationship between international treaty obligations, incorporated through domestic legislation, and pre-existing constitutional arrangements.

Verdict: The Supreme Court unanimously dismissed all grounds of appeal and answered in the negative all questions on which leave to appeal was granted.

Source: In the matter of an application by James Hugh Allister and others for Judicial Review [2023] UKSC 5