Promissory estoppel is an equitable doctrine that arises in the context of an existing contract: a promise, assurance or representation of some future conduct by a person is relied upon by another, such that a person relies on the promise of conduct to their detriment, and the promisor will not strictly rely on their strict legal rights, or a defence that would otherwise be available. The promise, assurance or representation must be clear and unequivocal. In essence, estoppel is a rule of evidence that prevents a party to legal proceedings denying the truth of a statement made by them.