Cheshire West was overruled on 2 June 2026. In the AGNI reference, a seven-justice Supreme Court panel held unanimously that the acid test of continuous supervision and control was wrong in principle. It replaced the test with the multifactorial assessment Strasbourg has applied since Engel and Guzzardi. A person who lacks capacity can now give valid consent to confinement.
What did the Supreme Court actually decide?
The case is 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. It was heard over three days in October 2025 and handed down on 2 June 2026. Lord Sales and Lady Simler gave the lead judgment. Lord Reed, Lord Hodge, Lord Lloyd-Jones, Lord Stephens and Lady Rose agreed.
The Attorney General for Northern Ireland had referred a proposed revision to the DoLS Code of Practice accompanying the Mental Capacity Act (Northern Ireland) 2016. The revision would tell professionals that a person aged 16 or over could consent to confinement by words or conduct showing contentment with their care arrangements. Capacity to decide on residence and care would not be required. That is not what P v Cheshire West and Chester Council [2014] UKSC 19 had said, and the reference could not be answered without confronting it.
The Court held the Revised Code compatible with Article 5, applied the 1966 Practice Statement, and overruled Cheshire West.
The multifactorial test replaces the acid test
At paragraph 53 the Court set out the position in eight numbered propositions. The starting point is the specific situation of the individual, assessed multifactorially, taking account of the type, duration, effects and manner of implementation of the measure. That is the approach in Engel v The Netherlands (1979-80) 1 EHRR 647 and Guzzardi v Italy (1981) 3 EHRR 333, applied consistently by the European court ever since. No single factor decides the question.
Several things become relevant that the acid test excluded. Compliance and absence of objection, where the person is capable of objecting or of tacit agreement, bear on the objective element of confinement. So does the relative normality of the placement. Where the facts are far from the paradigm of confinement in a cell, the purpose of the measure counts too.
The majority in Cheshire West, the Court held at paragraph 53(vi), had departed from that longstanding approach in setting out the acid test, and was wrong to do so.
Can a person who lacks capacity give valid consent?
Yes. This is the part of the judgment that changes daily practice most directly. Valid consent under Article 5 is an autonomous Convention concept. The Court was explicit at paragraph 53(ii) that it is not to be equated with legal capacity in domestic law, nor with the consent required to waive a Convention right. Paragraph 126 develops the distinction.
Take someone without legal capacity who is conscious of their environment, has a basic understanding of their living circumstances, and can express a view about it. Where they manifest acceptance of their situation, that opinion should be respected when the Article 5 assessment is made. The Court paired that with a caution at paragraph 53(v). Ascertaining the true feelings of a person who cannot decide on their own living arrangements is difficult, and the approach should be practical and realistic. Where there is serious doubt, no inference of valid consent should be drawn.
The Mental Welfare Commission for Scotland had intervened in broad support of a wider concept of valid consent. The Official Solicitor intervened to raise concerns about departing from Cheshire West.
Why the Court departed from its own decision
Overruling a twelve-year-old decision of the same court is rare, and the 1966 Practice Statement is the mechanism. The Court gave three reasons. The acid test had never been adopted in Strasbourg. It drew a bright line too crude for the situations it had to cover, and it read Article 5 over-extensively.
Paragraph 54 is worth reading in full for the picture it gives of who this affects. The Court set out the spectrum. Some people communicate through speech, some through Makaton or assistive technology, some through sounds or gestures. They live in their own homes, with parents or foster parents, in supported living with shared staff, or in care homes. It also recorded that care plans in a person’s own home can involve sedative medicine, physical restraint devices and electronic monitoring, measures with real potential to be overused or abused. Even a domestic setting, the Court said, can involve a deprivation of liberty.
That matters for how the judgment is read. This is not a decision that community care arrangements fall outside Article 5. It is a decision that whether they do requires an assessment rather than the application of a formula.
What happens to existing authorisations?
There is no grace period. The approach in Cheshire West must not be followed from the date of judgment. Every guidance document built on the acid test now has to be read in that light, and there are a great many of them.
Official output has followed steadily. The Department of Health in Northern Ireland issued interim practitioner guidance by HSC circular MCAU 1/26 on 23 June 2026. ADASS published an update note for directors of adult social services on 18 June. The Court itself anticipated more. At paragraph 55 it noted that the correct approach to the subjective element would logically affect every setting: hospitals, care homes, children’s homes, hostels, supported living and private homes. Further consideration will be needed.
Every Court of Protection and High Court authorisation made on the acid test now rests on a legal footing that no longer exists. Case law from 2014 to 2026 on whether particular facts amounted to a deprivation has to be treated with caution. For practitioners advising local authorities, care providers and families, a settled and content placement may no longer be a deprivation at all. The assessment has to be done, and it has to be recorded.
What should practitioners do now?
The immediate work is auditing. Live authorisations made on the acid test need identifying. The reasoning behind them needs revisiting against the multifactorial assessment rather than assumed to survive it. Care plans that were treated as deprivations because they met the acid test may not be, and the file needs to show why either way.
Evidence-gathering changes shape as well. Under the acid test, what the person thought about their placement was largely beside the point. It is now a powerful factor. The person’s expressed views, how they communicate them, and the basis on which anyone concluded they accepted or objected all need recording properly. Where there is serious doubt, paragraph 53(v) is the answer: draw no inference of consent.
The Supreme Court has been busy on rights questions this year. Readers following that line may want our reports on the Dillon (No 2) decision on the Troubles Legacy Act and the grant of permission in the Palestine Action proscription appeal.
The full judgment runs to considerable length and repays reading in the original. It is available on the Supreme Court case page, and members of 39 Essex Chambers have published a detailed practitioner summary.