Disputes over a loved one’s mental capacity are becoming a more common feature of contentious probate work. As people live longer, dementia, stroke-related cognitive impairment or other conditions affect decision-making, families are increasingly finding themselves arguing not only about what a will says, but about whether the person who made it was capable of making it at all. Roman Kubiak, partner in Hugh James’s private wealth disputes team, examines what impact the recent ruling in Croll v Estate of Margaret Mary Thorpe Deceased could have on capacity challenges.
Many families assume that once a court has looked at a person’s mental capacity, that is the end of the matter. If the Court of Protection has already ruled on someone’s capacity during their lifetime, it’s natural to think that this settles any later argument about whether a will they made is valid. A recent High Court decision shows that this assumption can be wrong, and that it can lead to costly and avoidable litigation.
In Croll v Estate of Margaret Mary Thorpe Deceased & Ors [2026] EWHC 2232 (Ch), which was an application by the defendants to strike out or dismiss the claimant’s claim seeking to “propound” (i.e. out to probate) a will which the Court of Protection had seemingly previously held to be invalid due to lack of capacity.
Master Clark, sitting in the High Court, considered whether a declaration made years earlier by the Court of Protection about a person’s capacity, and about the validity of his will, could bind the parties in a later probate dispute after his death. The judgment is a useful reminder that the Court of Protection and the High Court perform different functions, and that a will has no legal effect until the person who made it has died.
Background
The case arose out of a bitterly contested family dispute between three siblings, Julie, Peter and Jackie, following the deaths of their parents, Arthur and Margaret Thorpe.
Arthur suffered a stroke in 2017, at the age of 78, causing some cognitive impairment. The following year, the couple moved out of their home to live with their son, Peter. However, in June 2021 they split up. Margaret remained with Peter, while Arthur moved out to live with his daughter, Julie, the claimant.
Following the breakdown in the relationship, Arthur granted Julie lasting power of attorneys, giving her authority to manage his property and financial affairs and personal welfare. He also made a new will leaving his estate to Julie instead of Maragret, as set out by his earlier will made in 2001. He also began divorce proceedings against Margaret.
The following year, Arthur’s solicitor commissioned a doctor’s report which found that he lacked capacity to litigate. Soon afterwards, the Office of the Public Guardian applied to the Court of Protection to set aside the lasting powers of attorney Arthur had granted to Julie. In response, Jackie sought to have those lasting powers of attorney ruled invalid for lack of capacity, and to have the 2021 will revoked and the earlier 2001 will reinstated.
That dispute was heard in the Court of Protection in November 2023, at which point Arthur was still alive, though found to lack capacity. The Court of Protection ruled that the lasting powers of attorney were invalid and dismissed the divorce petition.
Significantly, the Court of Protection judge went further than just considering the lasting powers of attorney and the divorce petition. “The will cannot stand”, he said, noting that “a lucid moment for [Arthur] seems impossible on this evidence”. He produced a written order declaring the 2021 will invalid for lack of capacity and recommending that a statutory will be drawn up, though that never happened.
Arthur’s solicitor subsequently raised concerns about the validity of that declaration, pointing out that section 15 of the Mental Capacity Act 2005 appears to empower the Court of Protection only to make declarations about a person’s present capacity, not their capacity at a past date, and noting the earlier authority of Re M (Statutory Will) [2009] EWHC 2525 (Fam) to support the argument that the “Court of Protection has no jurisdiction to rule on the validity or invalidity of any will.”
Arthur died in April 2024. Margaret then changed her own will to leave her estate to Peter and Jackie, instead of Julie. Margaret died in May 2025. Soon afterwards, Julie sought to propoundArthur’s disputed 2021 will.
Peter and Jackie challenged it on the grounds of testamentary capacity, want of knowledge and approval, undue influence and fraudulent calumny (a specific type of undue influence where a person is alleged to “poison the mind” of someone making a will with a view to excluding another from benefit).
Both parents’ estates were therefore in dispute, as Margaret’s estate potentially included Arthur’s estate under his 2001 will.
Did the Court of Protection have jurisdiction to rule on the will’s validity?
Before the dispute over Arthur’s estate could proceed, the Court of Protection order needed to be resolved. That question was referred to the High Court, which ruled that it fell beyond the Court of Protection’s jurisdiction, for two independent reasons.
First, section 15 of the Mental Capacity Act 2005 permits the court to make declarations as to whether a person “has or lacks capacity to make a decision”. Master Clark held that “the wording of [section 15] clearly…limits the scope of the declarations pursuant to it to the relevant person’s capacity at the date of the declaration” and “does not extend to declarations as to past capacity”. This aligned with the concern that had previously been raised, and with the earlier authority of Re M (Statutory Will), which confirmed that the Court of Protection has no jurisdiction to rule on the validity or invalidity of any will.
Secondly, Master Clark held that a will has no legal effect until the death of the person who made it. As Arthur was still alive at the date of the Court of Protection decision, the 2021 will had not yet taken effect. “Issues as to the validity of the will as an effective testamentary disposition had therefore not yet crystallised”, said Master Clark, “and when they did, would be properly determinable only in a probate claim and not in the [Court of Protection]”.
Why declarations in the earlier proceedings did not determine the probate dispute
Master Clark held that the Court of Protection order could not give rise to an “issue estoppel” binding Margaret’s estate, or the related claims concerning Arthur’s will. Margaret had not been a party to the Court of Protection applications concerning Arthur’s capacity, and under ordinary principles of estoppel, a judgment only binds the parties to the proceedings in which it was given.
The effect of Master Clark’s ruling is that the Court of Protection’s order cannot be relied upon as having already determined whether Arthur had testamentary capacity in 2021. The question must instead be determined on the evidence in the High Court probate proceedings, applying the established common law test for testamentary capacity, rather than by reference to the Court of Protection’s earlier declaration.
Why this decision matters
For individuals making wills, the decision is a reminder that, but for the case of mutually binding wills, a will generally remains fully revocable, and its validity remains legally untested, until the moment of death. No court can pre-emptively strike down a will, or conclusively determine that a testator lacked capacity to make it, while that person is still alive.
For attorneys and deputies, the case shows that a Court of Protection finding on a person’s capacity to grant a power of attorney, or to manage their property and affairs, does not automatically extend to that person’s capacity to make a will. The two are governed by different legal tests, decided in different proceedings, and a Court of Protection order addressing one should not be treated as resolving the other.
For executors and beneficiaries, the case is a cautionary reminder against assuming that earlier Court of Protection litigation automatically determines the outcome of a will dispute. Where a beneficiary or executor was not a party to the Court of Protections proceedings, its findings will generally not bind them. In addition, a probate claim challenging a will may need to be argued afresh on the evidence, even where extensive capacity evidence already exists from Court of Protection proceedings during the testator’s lifetime.
The difference between mental capacity and testamentary capacity
A recurring source of confusion in cases like this is the assumption that “mental capacity” is a single, general concept that a person either has or lacks. Capacity is decision-specific. The Mental Capacity Act 2005 and the Court of Protection are in principle concerned with a person’s capacity to make particular decisions in the present, such as decisions about property and financial affairs, care and welfare, or specific transactions like granting a power of attorney.
In comparison, testamentary capacity is a distinct common law concept, which asks whether a person had the necessary understanding at the time they executed a will: understanding the nature of making a will and its effects, the extent of the property being disposed of, and the claims of those who might expect to benefit, without being influenced by any disorder of the mind. That test is currently laid out in the case of Banks v Goodfellow (1870) LR 5 QB 549 although the Law Commission has recently proposed reform to the law of wills which includes bringing the test in line with the statutory test under the Mental Capacity Act 2005. The draft Wills Bill 2025 is currently awaiting Parliamentary approval.
About the author
Roman Kubiak is a partner and head of Hugh James’ private wealth disputes team. He advises across the whole spectrum of private wealth disputes, with a particular focus on high value, complex and cross-border disputes including: trust disputes, breach of trust claims and applications to remove trustees; will disputes, particularly those with an international element; claims under the Inheritance (Provision for Family and Dependants) Act 1975; and claims for equitable relief under proprietary estoppel, constructive trusts and resulting trusts. He acts for high profile and high net worth individuals, financial institutions, professional trustees and executors and charities.
The views expressed in this article are those of the author and not necessarily those of Today’s Wills and Probate.
