City and Westminster Properties Ltd v Mudd [1959] Ch 129 FACTS: The defendant was a tenant of a lock up shop and slept in the office at the back of the shop, a fact which was known to the lessor. In 1947, during negotiations for a new lease, the defendant was sent a draft of a new lease containing a covenant by the lessee 'not to permit or suffer the demised premises or any part thereof to be used as a place for lodging, dwelling or sleeping'. The plaintiff's agent told the defendant that, if he signed the lease, the plaintiff would not object to his continuing to live in the shop. The defendant therefore signed in response to this assurance. Some years later, the plaintiff sought forfeiture of the lease on the ground of breach of this covenant. HELD: As the defendant had signed the lease only because of the promise by the plaintiff's agent, he was entitled to rely on that promise as long as he was in occupation of the shop.