Key takeaways
The Supreme Court has been reconsidering the Cheshire West ’acid test’
This could potentially redefine what constitutes a deprivation of liberty.
Case stems from the NI Department of Health seeking to revise its DoLS Code of Practice
To allow those who lack capacity to consent to their confinement through the expression of wishes and feelings.
Judgment being handed down on 2 June 2026
In the meantime, we recap on the case below.
Background
From 20-22 October 2025, the Supreme Court heard The Reference by the Attorney General for Northern Ireland (UKSC/2025/0042) – a case which could fundamentally reshape the legal test for determining a deprivation of liberty in the UK.
In short, the Supreme Court was asked by the Attorney General for Northern Ireland to determine whether a person aged 16 or over who lacks mental capacity to decide about their care or treatment can nonetheless give valid consent to arrangements that might otherwise amount to a deprivation of liberty under Article 5 of the European Convention for Human Rights (ECHR).
Under the ‘acid test’ derived from Supreme Court in P v Cheshire West and Chester Council and another [2014] UKSC 19 in 2014, a placement which involves continuous supervision and control and where the individual is not free to leave, amounts to a deprivation of liberty if the individual lacks capacity to consent to the arrangements, regardless of the individual’s compliance or apparent happiness with these arrangements.
The Reference made to the Supreme Court arose from a proposal by the Minister of Health to revise the Deprivation of Liberty Safeguards Code of Practice (the Code) (issued under the Mental Capacity Act (Northern Ireland) 2016) to allow persons aged 16 and over who lack capacity to make decisions about their care and treatment to give valid consent to their confinement through the expression of their wishes and feelings. The Minister of Health’s powers are limited by the Northern Ireland Act 1998 to the extent that the proposed revision may only be lawful if it is compatible with the rights protected by the European Convention on Human Rights including Article 5: ‘the right to physical liberty’.
This case has been informally coined ‘Cheshire West 2’ because it directly invites the Court to reconsider the ‘acid test’ definition of a deprivation of liberty as set out in the 2014 Cheshire West case and the meaning of ‘consent’.
The parties and interveners
The Attorney General for Northern Ireland (‘AG’) was the referring party, there were numerous respondents (Advocate General for Northern Ireland, Lord Advocate, Counsel General for Wales and Minister of Health) and interveners (Secretary of State for Health and Social Care, National Autistic Society, Mencap and Mind, The Mental Welfare Commission for Scotland and the Official Solicitor.
The AG asked the Supreme Court to determine whether the proposed revision of the Code was compatible with Article 5 of the ECHR. The crux of her argument was that capacity and consent are not synonymous terms; a person may lack decision-making capacity, but still express a genuine, autonomous preference to live in a particular setting in a particular way. If this expression of assent is treated as valid, the arrangements may fall out of the scope of Article 5 entirely. The AG is supportive of a more flexible approach driven by contextual factors, which reduces the need for formal deprivation of liberty authorisations where the individual in question appears content.
The various respondents and interveners adopted differing positions and the below summarises the written cases which have been published:
Lord Advocate (Respondent)
The Lord Advocate is the Senior Scottish Law Officer. Her position stresses that certain minimum procedural safeguards for the obtaining of consent are required in order for the proposed action to be lawful under the Convention. Drawing upon case law examples, she argues the safeguards, at minimum should be objectively established, recorded, periodically reviewed and follow the provision of all necessary information to the consenting individual. Therefore, the Lord Advocate argues that in appropriate circumstances ‘valid consent’ to a situation of confinement may be given by a person without legal capacity compatibly with Article 5 of the ECHR if the Court is satisfied that the correct procedural safeguards are in place, the question should be answered in the affirmative and any departure from the decision in Cheshire West is not required.
Secretary of State for Health and Social Care (Intervener)
The Secretary of State for Health and Social Care invited reconsideration of the ‘acid test’ in its entirety. He contended that the law took a wrong turn in Cheshire West, resulting in an excessively broad definition of deprivation of liberty which goes far beyond that definition as set out by the European Court of Human Rights for the purposes of Article 5. This view reflects longstanding concerns around DoLS backlogs and operational burdens incurred by the acid test.
Charities: Mind, Mencap and National Autistic Society (Intervener)
These charities opposed any weakening of Article 5 safeguards and urged the preservation of protections established by Cheshire West. They argued that the acid test provides clear, necessary protections for people with impairments such as autism and learning difficulties. They considered that obtaining consent from someone lacking mental capacity would be unsafe, risking the reclassification of restrictive or unnecessary settings as voluntary simply because an individual appears outwardly compliant.
The Official Solicitor (Intervener)
The Official Solicitor to the Senior Courts of England and Wales’s position is informed by her regularly acting as litigation friend to P in the Court of Protection proceedings, many of whom are deprived of their liberty. She argues that it is unclear how the Minister for Health has the power to revise the DoLs Code of Practise in the manner proposed, and that there is a real risk that persons who lack capacity to make decisions about their residence and care but through their expressed wishes are nonetheless perceived to consent their confinement, will be prevented from having access to justice. She brings attention to the fact that given that such persons are not detained per Article 5, they would have no means per Article 5 to test the lawfulness of detention. She urges the Court to consider her submissions and particularly to consider the apparent internal inconsistencies within the approach that the Attorney General provides and the absence of sufficient procedural safeguards in the amended DoLs Code as currently drafted.
The Mental Welfare Commission for Scotland (‘MWC’) (Intervener)
The MWC’s overarching function is to act in a manner which seeks to protect the welfare of persons in Scotland who have a mental disorder. It’s position is that if and when an adult is able to understand a situation and circumstance so as to express an opinion or feeling about it, that feeling can and should be given significant weight in the determination of a person’s consent to that arrangement. It argues that this can clearly indicate valid consent such as there would not, on the analysis of Article 5, be a deprivation of liberty. In their view, it would be contrary to the principles of encouraging those lacking capacity to take part as much as possible in the decision making surrounding their lives and welfare, as well as being contrary to the necessary balancing between Article 5 and 8 rights to deem such expressions from an adult irrelevant on a blanket basis. Therefore, the MWC agrees with the proposed revivals to the relevant Code of Practise, arguing that it would not be a breach of Convention Rights.
Conclusion
We are eagerly awaiting the Supreme Court’s judgment which could reshape the legal landscape for health and social care professionals and providers, alter the trajectory of the upcoming Liberty Protection Safeguards (LPS) consultation and subsequent implementation, and redefine what it means to be deprived of your liberty in the UK.
Watch this space for our analysis of the judgment once it is handed down on 2 June 2026.
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This article was co-authored by Paralegal, Kate Sheppard.
