A man promised to pay his wife £100 a year after their divorce. Relying on this, she didn’t apply for maintenance. The CA said it was an unenforceable agreement, since he, the promisor, had not asked her to do it. Denning LJ asserted that promissory estoppel can only be used to prevent someone from relying on their strict legal rights of going back on a promise. It is NOT a cause of action itself. LJ Birkett supported this, describing promissory estoppel as a “shield, not a sword). Denning LJ also said that promissory estoppel only applies to modifications of a contract, whereas contract formation itself still requires consideration. The doctrine of equitable estoppel gives no new rights. Denning said this was to prevent it clashing from the general requirement of consideration for establishing new contracts/new rights.