Allister & Peeples, Re Applications for Judicial Reviews (Northern Ireland)

Factual and Procedural Background

Two groups of applicants (collectively, “the appellants”) brought separate judicial-review proceedings challenging the lawfulness of the Protocol on Ireland/Northern Ireland, which forms part of the Withdrawal Agreement between the United Kingdom (“the UK”) and the European Union (“the EU”). The first proceedings were issued in March 2021 against the Secretary of State for Northern Ireland; the second were issued in February 2021 against the Prime Minister, the Secretary of State for Northern Ireland, and the Chancellor of the Duchy of Lancaster (collectively, “the respondents”).

Both applications were heard together in the High Court of Northern Ireland, where Judge Colton dismissed them on 30 June 2021 ([2021] NIQB 64). The Court of Appeal of Northern Ireland dismissed the ensuing appeals on 14 March 2022 ([2022] NICA 15). The Court of Appeal nevertheless granted limited permission to appeal to the UK Supreme Court on three discrete grounds. The present judgment—delivered by Judge Stephens for a five-member panel—addresses those three grounds.

Legal Issues Presented

1. Whether section 7A(3) of the European Union (Withdrawal) Act 2018 lawfully modifies Article VI of the Acts of Union 1800.
2. Whether any such modification effects an unlawful change in the constitutional status of Northern Ireland contrary to section 1(1) of the Northern Ireland Act 1998.
3. Whether the Protocol on Ireland/Northern Ireland (Democratic Consent Process) (EU Exit) Regulations 2020 were validly made under section 8C of the European Union (Withdrawal) Act 2018 and lawfully disapply section 42 of the Northern Ireland Act 1998 in the specific context of future consent votes.

Arguments of the Parties

Appellants’ Arguments

• The Protocol conflicts with the trade and treaty limbs of Article VI of the Acts of Union, which they describe as constitutional statutes conferring fundamental rights that cannot be impliedly repealed, suspended, or modified without express words.
• The treaty limb of Article VI imposes a statutory restriction on the Crown’s prerogative to make a treaty that fails to place the subjects of Northern Ireland on an equal trading footing with those of Great Britain; hence, the Protocol is ultra vires the prerogative.
• Section 1(1) of the Northern Ireland Act 1998 protects Northern Ireland’s status more broadly than the binary question of remaining in the UK or joining a united Ireland; any “substantial diminution” of that status—such as creating a customs border—requires prior approval in a border poll.
• The 2020 Regulations are ultra vires because (a) section 10(1)(a) of the 2018 Act limits delegated powers to acts compatible with the Northern Ireland Act 1998, and (b) disapplying the cross-community voting safeguard in section 42 of that Act is incompatible and an impermissible use of Henry VIII powers.

Respondents’ Arguments

• Even if the Protocol conflicts with Article VI, section 7A of the 2018 Act provides that all enactments—whenever made—are subject to the obligations arising under the Withdrawal Agreement, thereby lawfully modifying Article VI for as long as the Protocol applies.
• Section 1 of the Northern Ireland Act 1998 regulates only the choice between remaining part of the UK and joining a united Ireland; this Court’s decision in Miller (No 1) is dispositive.
• The 2020 Regulations fall squarely within section 8C(1)–(2) of the 2018 Act: democratic consent to Articles 5–10 of the Protocol concerns international relations, an excepted matter outside the Assembly’s devolved competence, so section 42 does not apply. Moreover, Parliament expressly authorised amendments of primary legislation via section 8C(2).

Table of Precedents Cited

Court's Reasoning and Analysis

Article VI Issue: The Court accepted, without revisiting, that the Protocol is inconsistent with Article VI. It held, however, that section 7A of the 2018 Act expressly provides that “every enactment” has effect subject to obligations under the Withdrawal Agreement. Because the Protocol’s trade restrictions are such obligations, Article VI is “modified to the extent and for the period during which the Protocol applies.” The Court rejected characterisations of suspension or implied repeal as academic; Parliament’s clear words prevail even over constitutional statutes.

As to the treaty limb of Article VI, the Court assumed—without deciding—that it could restrict the prerogative. Nevertheless, the 2020 Act’s long title and substantive provisions authorised the Government to conclude and implement the Withdrawal Agreement, thereby overriding any earlier statutory limitation.

Section 1 NIA 1998 Issue: Relying on Miller (No 1), the Court reaffirmed that section 1 only governs whether Northern Ireland remains in the UK or joins a united Ireland. Creation of an internal customs border does not trigger the statutory requirement for a poll.

2020 Regulations Issue: Article 18 of the Protocol, read with the UK’s unilateral declaration, obligated the UK to legislate for a democratic-consent mechanism based on simple majority voting. Under section 7A(3), that obligation modifies all enactments, including section 42 NIA 1998. Thus, when the Secretary of State used section 8C to make the Regulations, they were compatible with the Act as already modified. The Court further found section 8C(2) unambiguously authorises amendments to primary legislation, defeating the appellants’ Henry VIII challenge.

Holding and Implications

APPEALS DISMISSED.

The Court answered “No” to each certified question: section 7A lawfully modifies Article VI; that modification does not breach section 1(1) NIA 1998; and the 2020 Regulations were validly made. The immediate consequence is that the Protocol, including its democratic-consent mechanism, remains fully operative in UK domestic law. The decision turns on clear statutory wording and does not announce any novel constitutional doctrine, but it reaffirms Parliamentary sovereignty and the potency of section 7A as a mechanism for incorporating international obligations into domestic law.