D had trouble with lorries that he had was using on a hire-purchase basis from P, and P had said that he could delay payment while the lorries were being fixed by the plaintiffs and not in active service. When P sued D for overdue instalments owed from the point when the lorries were available for use again, D claimed equitable estoppel, in that they had not been given reasonable notice that the lorries were available for use again. Privy Council held that promisory estoppel (PE) applied where one party, in absence of consideration, agreed not to enforce his rights. However there are 3 qualifications: (1) that the party claiming PE had altered his position; (2) that the promisor could revoke his promise once reasonable notice had been given; (3) the promise was only irrevocable where the promise couldn’t resume his former position. In this case the position of D had not been altered AND the lorries had been made available to him with reasonable notice.