In Singh Bains v Irshad [2025] EWHC 491 (Ch), HHJ Paul Matthews (sitting as a Judge of the High Court), under the heading 'Proprietary estoppel' said, at paragraphs 262 to 266:
'The moral structure of the common intention constructive trust is in substance identical to that of the earlier doctrine of proprietary estoppel, from which it appears to have sprung in Gissing v Gissing [1972] AC 886, HL. One person (A) either promises or reasonably induces in another (B) the expectation that B shall have an interest in property belonging to A. It is not a contract, because no consideration is sought or provided (and, even if so, any formality requirement is not fulfilled). But there is a common intention (whether actual or by estoppel) that that shall happen. Being intended so to rely, B then relies on the promise or expectation to his or her detriment. If the court holds that it is unconscionable for A not then to perform the promise or make good the expectation, the court may in its discretion so order.
In Gillett v Holt [2001] Ch 210, CA, Robert Walker LJ, with whom Beldam and Waller LJJ agreed, said (at 225):
" … the fundamental principle that equity is concerned to prevent unconscionable conduct permeates all the elements of the doctrine. In the end the court must look at the matter in the round."
Thorner v Major [2009] 1 WLR 776 was one of a pair of cases in which the doctrine of proprietary estoppel was considered in the House of Lords. Lord Scott said
"15. Lord Walker, in paragraph 29 of his opinion, identified the three main elements requisite for a claim based on proprietary estoppel as, first, a representation made or assurance given to the claimant; second, reliance by the claimant on the representation or assurance; and, third, some detriment incurred by the claimant as a consequence of that reliance. These elements would, I think, always be necessary but might, in a particular case, not be sufficient. Thus, for example, the representation or assurance would need to have been sufficiently clear and unequivocal; the reliance by the claimant would need to have been reasonable in all the circumstances; and the detriment would need to have been sufficiently substantial to justify the intervention of equity."
In the same case, Lord Walker said:
"56. I would prefer to say (while conscious that it is a thoroughly question-begging formulation) that to establish a proprietary estoppel the relevant assurance must be clear enough. What amounts to sufficient clarity, in a case of this sort, is hugely dependent on context. I respectfully concur in the way Hoffmann LJ put it in Walton v Walton (in which the mother's 'stock phrase' to her son, who had worked for low wages on her farm since he left school at fifteen, was 'You can't have more money and a farm one day'). Hoffmann LJ stated at para 16:
'The promise must be unambiguous and must appear to have been intended to be taken seriously. Taken in its context, it must have been a promise which one might reasonably expect to be relied upon by the person to whom it was made'."
In Guest v Guest [2024] AC 833, SC, Lord Briggs (with whom Lady Arden and Lady Rose agreed) said:
"13. … The true purpose, as recognised by the Court of Appeal in the present case, is dealing with the unconscionability constituted by the promisor repudiating his promise. It is wrong to treat the unconscionability question as limited to the issue whether or not an equity arises, and then to leave it out of account when framing the remedy."
Collatory Case Series
The Collatory Case Series, is an series of bulletins, designed to report that one case which collates the essential principles/propositions of law, for a particular doctrine/area of law (and perhaps, sometimes, provide a few extra citations/quotations etc.). It is not designed as a deep and comprehensive review of an area of law, but to provide that quick 'go to' case.
SIMON HILL © 2026*
BARRISTER
33 BEDFORD ROW
NOTICE: This article is provided free of charge for information purposes only; it does not constitute legal advice and should not be relied on as such. No responsibility for the accuracy and/or correctness of the information and commentary set out in the article, or for any consequences of relying on it, is assumed or accepted by any member of Chambers or by Chambers as a whole, or the Copyright holder. No attempt has been made to provide an exhaustive review/account of the law in this area. *Copyright is owned by Barrister Search Limited.