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Case details

In the matter of an application by Clifford Peeples for Judicial Review (Appellant) (Northern Ireland)

Case ID: 2022/0089

Case summary


In these conjoined appeals, the appellants challenge the lawfulness and constitutionality of the respondents’ decisions and actions in the negotiating, implementing, and operating of the Northern Ireland Protocol (the "Protocol"). The issues raised concern the constitutional settlement of the UK, the operation and interpretation of the Belfast Agreement, and the effect of the Withdrawal Agreement and the Protocol in domestic law.

The grounds of appeal are, among others, the claimed incompatibility of the Protocol and related regulations with the Act of Union 1800 and section 1 of the Northern Ireland Act 1998, the correct approach to statutory interpretation to resolve a conflict or clash between the constitutional provisions of constitutional Acts, and the lawfulness of the Protocol.


The Referendum on 23 June 2016 resulted in a majority across the UK deciding to leave the EU. Withdrawal from the EU was given effect in domestic law by a series of legislative steps. First, the UK Parliament passed the European Union Notification of Withdrawal Act 2017. Then, the European Union Withdrawal Act 2018 (the "2018 Act") was passed which repealed the European Communities Act 1972. Subsequently, the European Union Withdrawal Agreement Act 2020 (the "2020 Act") was passed amending the 2018 Act and providing for the formal execution and ratification of the Withdrawal Agreement between the UK and the EU, including the Protocol. The Withdrawal Agreement came into operation on 1 February 2020, the Protocol came into operation on 10 December 2020. The transition period ended on 31 December 2020 with the result that final withdrawal from the EU took effect from 1 January 2021.

The Protocol contained bespoke arrangements to ensure continued co-operation between Northern Ireland ("NI") and the Republic of Ireland following the UK’s withdrawal from the EU, the avoidance of a hard border between them, and protection of the agreements for peace between the communities of NI. The Protocol creates a customs and regulatory border between NI and the UK in specified areas of trade, while positioning NI primarily in the EU internal market. As such, the Protocol subjects NI to a uniquely regulated trading regime until 2025.

The appellants brought judicial review applications challenging the Protocol. They argued that the Protocol is incompatible with the Act of Union 1800, and specifically with Article VI which provides that the subjects of Great Britain and Ireland shall be on the same footing with respect to trade, and that any future treaty entered into with a foreign power shall preserve that footing. They also argued that the Protocol breached the Northern Ireland Act 1998, specifically section 1(1) which provides that "Northern Ireland in its entirety remains part of the United Kingdom and shall not cease to be so without the consent of the majority of the people of Northern Ireland voting in a poll…", as well as the European Convention on Human Rights.

The judge at first instance dismissed the judicial review application. The judge held that both the Act of Union and the 2018 and 2020 Acts are of constitutional character and are constitutional statutes and that where two constitutional statutes appear to conflict, the fundamental principle of interpretation is that the more recent statute be preferred. The judge also held that the constitutional character of the 2018 and 2020 Acts should be seen in the context of the modern constitutional arrangements for NI. The more general words of the Act of Union 1800 written over 200 years ago in entirely different economic and political circumstances could not override the clear specific will of Parliament as expressed in legislation in the modern constitutional context. The appellants appealed to the Northern Ireland Court of Appeal.

The Northern Ireland Court of Appeal dismissed the appeal, holding that Article VI of the Act of Union 1800 has been modified and not impliedly repealed by the 2018 and 2020 Acts. There is no conflict with section 1(1) of the Northern Ireland Act 1998 as the constitutional status of NI within the UK has not changed and cannot change other than by virtue of the mechanism provided by section 1(1) by way of democratic consent. The appellants now appeal to the Supreme Court.

Judgment appealed

[2020] NICA 15



Clifford Peeples


Secretary of State for Northern Ireland



Lord Reed, Lord Hodge, Lord Lloyd-Jones, Lord Sales, Lord Stephens

Hearing start date

30 November 2022

Hearing finish date

1 December 2022