In Secretary of State for Northern Ireland v Dillon & others [2026] UKSC 15, the Supreme Court has handed down a judgment of constitutional significance relating to the scope of the power of the Northern Irish courts to strike down primary legislation for inconsistency with rights protected by the Belfast Good Friday Agreement, and the particular role afforded to it by Article 2(1) of the Windsor Framework (“WF”), formerly known as the Northern Ireland Protocol to the UK-EU Withdrawal Agreement.
The case concerns a challenge to the highly controversial Northern Ireland (Legacy and Reconciliation) Act 2023, which brought to an end all criminal investigations, inquests and civil litigation arising out of the Troubles. Both the High Court and the Court of Appeal in Northern Ireland held that most of the Act was not only incompatible with the procedural obligation in Article 2 ECHR, but also breached Article 2(1) WF. Article 2 WF is a constitutionally novel provision. It obliges the UK to ensure that withdrawal from the EU does not lead to a diminution of the rights, safeguards and equality of opportunity provisions of the Belfast Good Friday Agreement. A series of cases litigated in Northern Ireland since Dillon have interpreted the scope and effect of Article 2(1) WF broadly, leading to the striking down of provisions of, for example, the Illegal Migration Act 2023.
The appeal also challenged conclusions of the Northern Ireland Court of Appeal that certain specific measures in the Legacy Act are incompatible with Article 2 ECHR, in particular the controls set out in the Act over disclosure to parties of national security information and the absence of legal aid for next of kin to participate in investigations carried out by the Independent Commission for Reconciliation & Information Recovery.
The Supreme Court has unanimously allowed the Secretary of State’s appeal on both the WF and the ECHR issues. It holds that Article 2(1) WF, read with the relevant provisions of the Belfast Good Friday Agreement, does not have direct effect so as to enable a challenge to the Legacy Act. As a result, the WF did not provide the domestic courts with power to strike down the legislation. The approach which has been adopted by the Northern Irish courts in relation to the WF will require significant revisiting. It holds that the investigative functions of ICRIR are capable of being operated compatibly with Article 2 ECHR, and that the lower courts had erred by assuming that adversarial inquest procedures in relation to the Troubles were the only Article 2-compliant mechanism.
Christopher Knight KC was instructed to join the counsel team for the Secretary of State for Northern Ireland for the appeal to the Supreme Court, with a particular focus on the Windsor Framework issues. He was instructed by the Crown Solicitors Office, led by Tony McGleenan KC CBE and Sir James Eadie KC.
The judgment of the Supreme Court may be found here.
