Equitable Estoppel in UK Law

Moreover the fundamental principle that equity is concerned to prevent unconscionable conduct permeates all the elements of the doctrine.

On the other hand, equitable estoppel requires an unequivocal representation by one party that he will not insist upon his legal rights against the other party, and such reliance by the representee as will render it inequitable for the representor to go back upon his representation.

It can be said that there is a case for reform of the law, which has to be discovered in a number of diverse rules based on no coherent line of reasoning. But in practice masters and judges, for whom the problem is of almost daily occurrence, manage to solve it without any great difficulty.

In my opinion it is a necessary element of proprietary estoppel that the assurances given to the claimant (expressly or impliedly, or, in standing-by cases, tacitly) should relate to identified property owned (or, perhaps, about to be owned) by the defendant. The latter need not be based on an existing legal relationship, but it must relate to identified property (usually land) owned (or, perhaps, about to be owned) by the defendant.

Proprietary estoppel typically consists of asserting an equitable claim against the conscience of the "true" owner. It is to be satisfied by the minimum award necessary to do justice ( Crabb v Arun District Council [1976] Ch 179, 198), which may sometimes lead to no more than a monetary award. A "common intention" constructive trust, by contrast, is identifying the true beneficial owner or owners, and the size of their beneficial interests.

An "estoppel" bars the object of it from asserting some fact or facts, or, sometimes, something that is a mixture of fact and law, that stands in the way of some right claimed by the person entitled to the benefit of the estoppel. The estoppel becomes a "proprietary" estoppel - a sub-species of a "promissory" estoppel - if the right claimed is a proprietary right, usually a right to or over land but, in principle, equally available in relation to chattels or choses in action.

Nor do they cast doubt on the general principle that the court should be very slow to introduce uncertainty into commercial transactions by over-ready use of equitable concepts such as fiduciary obligations and equitable estoppel. That applies to commercial negotiations whether or not they are expressly stated to be subject to contract.