Conway v Conway: Proprietary Estoppel, Family Promises and the Limits of Informality

Family farming disputes are fertile ground for proprietary estoppel claims.  However, the High Court’s recent decision in Conway v Conway [2025] EWHC 33314 (Ch), on appeal following a first instance decision in the County Court, provides a timely reminder that, as powerful a remedy as proprietary estoppel can be it isn’t a panacea.  The law remains sceptical of informal promises, particularly where they collide with statutory formalities governing land transactions.

While proprietary estoppel continues to provide a route to relief in appropriate cases, Conway illustrates the courts’ increasing insistence on clarity, evidence and proportionality. As we consider in this week’s edition of Field Notes, it also provides an important discussion of the relationship between equitable doctrines and the formal requirements of the Law of Property (Miscellaneous Provisions) Act 1989.

The factual background

The dispute arose from a familiar pattern in family farming: informal assurances about future ownership, reliance by a family member, and a subsequent breakdown in relationships.

The appellant, Peter Conway, was the registered owner of “Church Farm”, which included 20+ acres of land and buildings including a property known as “The Barn”. In March 2019, discussions took place between the appellant and the respondents, being his cousin, Stephen Conway, and his wife Amber Meek, who were interested in buying The Barn from Mr Conway. A purchase price of £150,000 was agreed orally, a figure significantly below market value to reflect the works that would be required to renovate the property into a residence for Stephen and Amber and their children. However, key terms, including whether there would be a “buy-back option” for Peter, were still not agreed when the respondents commenced renovation works.

For the next two years, Stephen and Amber spent over £230,000 renovating The Barn into their dream home, with the payment of £150,000 to Peter being deferred while works were ongoing, with Stephen and Amber making interim payments of £600 per month to Peter. However, while attempting to belatedly formalise their oral agreement, the relationship between Peter and Stephen and Amber broke down and in 2022 Peter issued a claim seeking a declaration that Stephen and Amber were not entitled to enter Church Farm, along with an injunction preventing access and damages for trespass. Stephen and Amber promptly filed a defence and counterclaim based on proprietary estoppel seeking The Barn’s transfer to them and injunctive relief enabling them to access the property.

In the County Court at first instance, Stephen and Amber’s counterclaim succeeded, with the court finding a clear assurance by Peter, “clear-cut” reliance by Stephen and Amber, and considerable detriment suffered in the form of “vast sums of money spent” and the “substantial time they invested” carrying out the renovations. The County Court made an order enforcing the oral agreement to sell the property to Stephen and Amber for £150,000 with no buy-back option for Peter. The decision was subsequently appealed by Peter, taking the matter to the High Court.

The legal framework: proprietary estoppel revisited (again)

On appeal, the High Court reaffirmed the orthodox elements of proprietary estoppel (considered in more detail in previous editions of Field Notes):

• Assurance: a clear and unequivocal representation or promise – in this case relating to rights in land.
• Reliance: the claimant must have relied on that assurance.
• Detriment: reliance must have resulted in substantial detriment.
• Unconscionability: it must be unconscionable for the promisor to resile from the assurance.

Vague statements of future intention are not enough, expressions of hope or expectation do not amount to binding assurances, and the Court was clear that the fact assurances were made in the context of family relationships does not lower the evidential threshold.  The court drew a clear line between genuine promises and what it described, in substance, as “familial optimism”.

The Law of Property (Miscellaneous Provisions) Act 1989

A central issue in Conway was the interaction between proprietary estoppel and the statutory formalities governing land contracts.

Section 2(1) of the Law of Property (Miscellaneous Provisions) Act 1989 requires that contracts for the disposition of an interest in land must:

• be in writing;
• incorporate all expressly agreed terms; and
• be signed by or on behalf of each party.

There are some exclusions - section 2(5) contains an express exception for "resulting, implied or constructive trusts" – but nothing in section 2(5) explicitly mentions proprietary estoppel.

Peter’s alleged assurances failed to satisfy the requirements of section 2(1). The question for the High Court was whether, in light of section 2(5), proprietary estoppel could nonetheless operate to circumvent the statutory scheme.

Proprietary estoppel as a form of constructive trust

Proprietary estoppel can function as a form of constructive trust, in that it enables courts to prevent a landowner/promisor from enforcing their strict legal rights when, by offering assurances and promises, they have encouraged another to reasonably believe that they will acquire an interest in the land. If the claimant acts to their detriment based on this promise, equity can intervene to prevent unconscionability, which can mean imposing a constructive trust – declaring that the promisor (or, perhaps, their estate) hold land on trust for the promisee to satisfy the claim.

However, the Court in Conway reiterated that proprietary estoppel is not a mechanism for undermining Parliament’s intentions and circumventing section 2(1). This meant that in Conway the Court considered that even where proprietary estoppel was made out, section 2 of the Law of Property (Miscellaneous Provisions) Act 1989 precluded it from granting specific performance of an (invalid) oral contract for the sale of an interest in land, as such relief would effectively enforce a contract that Parliament had declared void. The doctrine is an equitable safety valve, not an alternative route to enforce informal land agreements.

In particular, the Court emphasised that:

• equity will not enforce what is, in substance, an incomplete or uncertain land contract dressed up as estoppel;
• the court must be alive to attempts to use proprietary estoppel to sidestep statutory formalities; and
• the stronger the resemblance to a failed land contract, the stronger the evidential burden on the claimant.

This is significant. The Court’s reasoning signals a tightening of the boundaries between equity and statute. Proprietary estoppel remains available, doesn’t override the requirements of the 1989 Act.

Remedies

On remedy, the Court reiterated the principle that the aim of proprietary estoppel is not to fulfil expectations but to avoid unconscionability. Any award must be proportionate to the detriment suffered, not the promise allegedly made. In Conway, this meant resisting the temptation to award a wholesale transfer of property based on uncertain and informal assurances. As Stephen and Amber had put their case on an “all-or-nothing” basis they were at risk of receiving nothing despite all their time and expense renovating The Barn. Justice is still key though, and the court recognised the existence of a proprietary estoppel in Stephen and Amber’s favour and that it would be “deeply unfortunate and unjust” for there to be no remedy at all. The High Court accordingly remitted the matter to the County Court for determination of another equitable remedy, such as compensation, which would satisfy the established equity in Stephen and Amber’s favour but without enforcing a void contract.

Why Conway matters for farming families

The practical implications of Conway v Conway are potentially stark.

First, it confirms that informal succession arrangements sit on legally fragile foundations. Conversations in farm kitchens, however sincere, do not displace the formal requirements of land law.

Secondly, it demonstrates that proprietary estoppel is no longer treated as a broad-brush instrument of fairness. Courts are increasingly reluctant to convert family expectations into proprietary rights, particularly if doing so would conflict with statutory formalities.

Thirdly, it underscores that succession planning is not merely prudent but legally essential. Where farming families fail to document intentions, they leave their futures to the narrow and uncertain margins of equity.

Conclusion

Conway v Conway is not a rejection of proprietary estoppel, but it could be seen as a clarification of its limits. The Court has made clear that equity will not routinely rescue families from the consequences of informality, nor will it be used to circumvent or bypass section 2 of the Law of Property (Miscellaneous Provisions) Act 1989 where proprietary estoppel would result in enforcing a void agreement.

For farmers and landowners, the message is unmistakable: if the future of the farm matters, it is more important than ever that it is recorded, structured and documented in a legally sound way, not just informally promised.  Otherwise, when succession is left to assumption, the Court becomes the final arbiter of who owns the land, which is expensive, time consuming and stressful for everyone involved.

How we can help

The team here at Charles Russell Speechlys includes property specialists who can ensure that any proposed disposals of interests in land comply with all required formalities, while our agricultural and landed estate lawyers can offer guidance on the current beneficial ownership of your property as well as advise on any future or existing proprietary estoppel claim you are concerned about.

Field Notes is Charles Russell Speechlys’ weekly agricultural law blog, sharing plain-English insight into the legal and policy issues affecting agriculture, agricultural land and rural business life. From hints and tips on avoiding agricultural disputes, pitfalls to keep an eye out when planning for tenancy or family agri-business succession, to the latest agricultural legislative or policy changes and the most interesting farm-related court decisions, Field Notes makes the complex more understandable, always grounded in the realities of life on (and off) the land.

Field Notes comes out every Wednesday. Previous editions of Field Notes include:

• Is it "agricultural"? What actually counts as a matter of law?
• Agricultural law review 2025/2026: Key cases and legislation in 2025 and what’s ahead in 2026
• Agricultural policy review 2025: Key changes and what to expect in 2026
• A farm legal resilience checklist: 10-Minute audit to protect your business in 2026
• Cobden v Cobden: the Court of Appeal revisits exceptional circumstances and “proprietary estoppel-ish” equity on dissolution of a farming partnership