Double Direct Effect? The UK Supreme Court’s revisiting of the direct effect conditions in Dillon

Dr Eleni Frantziou, Associate Professor in Public Law and Human Rights, Durham Law School, and Dr Sylvia de Mars, Reader in Transnational Public Law, Newcastle Law School Photo credit: Samuel Lennox, via Wikimedia Commons Introduction Is there anything left to say on the direct effect of EU law? Yes, according to the UK Supreme Court, which handed down its much-awaited judgment in Dillon et al on 7 May 2026. The UK reference above is not a typo: despite Brexit, aspects of the EU/UK Withdrawal Agreement (‘WA’) have direct effect under the conditions provided for in EU law, in line with Article 4 WA. In Dillon, the UK Supreme Court was asked to interpret whether one provision of this agreement – Article 2(1) of the Ireland/NI Protocol (‘Protocol’), which is itself a core part of the WA (Article 182 WA) – is directly effective and, if so, on what terms. The case concerned the Legacy (Troubles and Reconciliation) Act 2023, which set out a broad range of immunities for serious crimes…