On 2 June 2026, the Supreme Court handed down one of the most significant judgments in mental capacity law in over a decade. In a unanimous ruling, seven justices overturned the long-standing Cheshire West decision that has shaped how deprivation of liberty is assessed in care and health settings since 2014. The implications are immediate; there is no transition period, and they directly affect how the Court of Protection operates, who needs formal authorisation for their care arrangements, and what legal rights families and individuals can access.
If you have a loved one in a care home, hospital, or supported living arrangement, or if you are involved in any proceedings relating to mental capacity, this judgment changes the landscape you are operating in.
What the Cheshire West Decision Was
To understand what has changed, it helps to understand what existed before. The 2014 Supreme Court ruling in P v Cheshire West established what became known as the “acid test” for determining whether a person lacking mental capacity was being deprived of their liberty under Article 5 of the European Convention on Human Rights. Under that test, if a person was under continuous supervision and control and was not free to leave, they were considered to be deprived of their liberty regardless of whether they appeared content with their arrangements or showed no sign of objecting.
The practical effect was wide-reaching. Large numbers of people in care homes and hospitals were caught by the acid test, requiring formal DoLS authorisations, and local authorities faced significant operational pressures as a result.
What the Supreme Court Has Now Decided
In AG for Northern Ireland [2026] UKSC 16, the Supreme Court has reset the law on deprivation of liberty by unanimously overruling the 2014 Cheshire West judgment and rejecting the acid test, returning to a multifactorial, context-sensitive approach which aligns with Strasbourg jurisprudence on the Article 5 right to liberty.
The key change is that the assessment of deprivation of liberty is no longer a bright-line test. Instead, it requires a multifactorial evaluation of the individual’s specific situation. Crucially, the judgment reintroduces a meaningful subjective element. Under Cheshire West, a person’s lack of objection and compliance was treated as irrelevant. The Supreme Court has now reversed that position: an individual’s experience of the arrangements is now central, with objection tending strongly towards a finding of deprivation of liberty, and contentment pointing the other way.
In plain terms, a person in a care home who lacks mental capacity but whose wishes and feelings indicate agreement with their placement may no longer be considered deprived of their liberty. The coercive element, whether the individual’s will is being overridden, is now a central consideration.
What This Means in Practice
For practitioners across social care and health, the impact is immediate and significant, with no transition period: the Cheshire West acid test no longer applies.
For families, this cuts both ways. On the one hand, some people who were previously subject to formal DoLS authorisations and the associated Court of Protection oversight may no longer require them. That could reduce the bureaucratic burden in cases where a person is genuinely settled in their care environment, and no coercion is involved.
On the other hand, the shift to a multifactorial assessment means that determining whether someone is being deprived of their liberty is now less straightforward without legal advice. Cases that might previously have been clearer under the acid test now require a more nuanced analysis. For families who have concerns about a loved one’s care arrangements or want to understand what protections remain in place, seeking advice from mental capacity solicitors is now an important step.
Legal Aid and the Court of Protection
One thing the Supreme Court judgment does not change is the availability of legal aid for certain Court of Protection proceedings. Where someone is challenging a deprivation of liberty safeguards authorisation, legal aid remains available on a non-means-tested basis, meaning access to a solicitor does not depend on the individual’s income or assets. For other Court of Protection welfare applications, legal aid is means-assessed
Solicitors Who Can Help
Given how recently this judgment has been handed down, specialist legal advice is particularly important right now. The following firms have established practices in the Court of Protection and mental capacity work:
Welford Solicitors focus exclusively on mental capacity law and health and welfare Court of Protection cases. Notably, they handle emergency Court of Protection applications where immediate legal intervention is required, such as urgent medical treatment or hospital discharge disputes nd they offer legal aid for Court of Protection cases, managing the entire eligibility process on behalf of clients. They act for families across England and Wales.
Hodge Jones & Allen are ranked in both the Legal 500 and Chambers UK 2026 for mental capacity and deputyship work. Based in London, they have a specialist team with experience across a wide range of Court of Protection matters.
Duncan Lewis Solicitors are ranked and recommended by the Legal 500 UK for Court of Protection and mental capacity work, with particular experience in health and welfare proceedings, DoLS challenges, and Section 21A Mental Capacity Act applications.
Clarke Willmott has specialist Court of Protection lawyers operating across multiple UK offices, including London, Manchester, Bristol, Birmingham, Cardiff, Southampton, and Taunton, and are recognised in Chambers 2026 for their work in this area.
Stephensons Solicitors have extensive experience in mental capacity disputes and best interests decisions, including welfare decisions relating to residence, care, contact, and medical treatment, and advise on DoLS challenges and Section 21A applications.
What Families Should Do Now
If you are involved in any existing Court of Protection proceedings, or if you have a family member in a care or hospital setting whose arrangements you have questions about, the judgment of 2 June 2026 is relevant to you. The legal framework has shifted, and it is worth reviewing your specific situation with a solicitor experienced in this area, particularly given that the new multifactorial approach means individual circumstances now carry considerably more weight than they did under the acid test.
