Cheshire West 2.0 – Supreme Court to Revisit Capacity and Consent

By: Avaia Williams

Committee Member, Avaia Williams, is a children and Court of Protection barrister who regularly acts in cases where the issue of capacity is raised.

On 20 October 2025, the Supreme Court is set to hear a case that may prove as significant for mental capacity law as the Cheshire West case itself. The reference, brought by the Attorney General for Northern Ireland, asks whether the Minister of Health in Northern Ireland can lawfully revise the Code of Practice under the Mental Capacity Act (Northern Ireland) 2016 so that a person who lacks capacity to decide about their living arrangements may nonetheless be treated as giving valid consent to confinement if their “wishes and feelings” indicate assent.

At the heart of the reference lies a challenge to the earlier Supreme Court judgment in Cheshire West v P [2014] UKSC 19. In that case, it was held that Article 5 of the European Convention on Human Rights applies to individuals who lack capacity and are under continuous supervision and control, regardless of whether they appear content. The so-called “acid test” was designed to ensure that safeguards and court oversight were triggered precisely because those individuals could not, in law, consent to confinement. The Attorney General for Northern Ireland argues that where a person’s wishes and feelings show contentment with their circumstances, that can amount to “consent,” meaning Article 5 is not engaged and no formal deprivation of liberty authorisation is needed.

Although the Code in question is specific to Northern Ireland, the issues that the Supreme Court must grapple with are of UK-wide importance and any judgment would apply domestically. The case squarely raises the question of whether Cheshire West went too far in treating all apparent confinement of incapacitated individuals as a deprivation of liberty. The Supreme Court itself has signalled that the proposed Northern Irish approach is “different” from Cheshire West, and the involvement of the UK Government and national charities such as the National Autistic Society, Mencap, and Mind underlines the breadth of interest. Whatever the Court decides will reverberate in England and Wales as much as in Belfast.

If the Attorney General succeeds, the landscape of Court of Protection work could change dramatically. At present, the application of the acid test has led to a large volume of cases requiring authorisation or review, post Cheshire West we saw a 33-fold increase. If “wishes and feelings” can operate as valid consent even in the absence of capacity, many of these situations will fall outside Article 5 altogether. The immediate consequence would be a drastic reduction in the number of cases requiring formal scrutiny.

That reduction may appear administratively attractive, but it raises searching questions about how disputes will be resolved. The current system provides clear statutory avenues for challenge, such as applications under section 21A of the Mental Capacity Act 2005. Those routes bring with them procedural safeguards, non-means-tested legal aid for the person at the centre of the case, and judicial oversight of decisions that deeply affect liberty and family life. If Article 5 is no longer engaged, those gateways close. Families and advocates may be left with judicial review as the only means of testing a decision, or with claims under Articles 8 and 3 of the Convention rather than Article 5. Judicial review, however, is procedurally different, access to legal aid changes, it is subject to short time limits, and it is not designed for the kind of fact-sensitive welfare inquiries the Court of Protection regularly undertakes.

The evidential terrain would also shift. Much greater emphasis would be placed on documenting the wishes and feelings of the person said to lack capacity. Professionals would be under pressure to demonstrate that any apparent contentment amounted to genuine consent. That, in turn, is likely to generate disputes about how those expressions were elicited, whether the person truly understood what was being asked, and the extent to which acquiescence may have been shaped by dependency, communication difficulties, or subtle coercion. The line between a best-interests judgment that respects preferences and a legal conclusion that the person has “consented” will be difficult to draw.

For practitioners concerned with access to justice, the implications are stark. Non-means-tested legal aid has been a crucial feature of deprivation of liberty challenges, ensuring that the most vulnerable individuals could be represented without their families bearing the financial burden. If fewer cases qualify as Article 5 deprivations, fewer cases will attract automatic public funding. More work will have to proceed through judicial review or human rights claims, both of which are subject to different funding regimes. 

This case is one to watch closely. It promises to redefine what counts as a deprivation of liberty, and in doing so could redraw the map of publicly funded representation in this area. If the Attorney General is successful, there will be fewer cases in the Court of Protection, less routine judicial oversight of confinement, and greater reliance on the proper documentation of wishes and feelings. 

The Supreme Court’s decision will therefore not only determine the future of the acid test but also shape how liberty is protected for those who cannot speak for themselves, and whether legal aid lawyers can continue to play the central role in securing their rights.