The world post AGNI: practical considerations

Adam Weisz, Kings Chambers

The Supreme Court’s judgment in A Reference by the Attorney General for Northern Ireland of a devolution issue under paragraph 34 of Schedule 10 to the Northern Ireland Act 1998 [2026] UKSC 16 (“AGNI”) represents a significant turning point in mental capacity law. Handed down on 2 June 2026, the decision overturns the approach established in P v Cheshire West and Chester Council & Anor [2014] UKSC 19 (“Cheshire West”), a case that has shaped how Article 5 of the European Convention on Human Rights is applied to those lacking the legal capacity to make decisions about their residence arrangements.

In AGNI, the Supreme Court overturned Cheshire West and introduced a new “multifactorial test” for assessing whether individuals who lack capacity are deprived of their liberty within the meaning of Article 5. The judgment has wide-ranging implications for practitioners, public bodies, and those supporting individuals with mental impairments.

This article, written by barristers Sam Karim KC and Adam Weisz of Kings Chambers, examines the key principles arising from AGNI, considers how the decision changes the legal landscape, and explores the practical implications for those working in mental capacity law.