A lock for a door (10) comprises a casing (11), a bolt (55), a pivoted operation handle (36), operable to retract the bolt, a locking member to deadlock the bolt against retraction, and a unitary spring steel connecting member (49) between the handle and the locking member. The connecting member has a central coil (56) around a rod (43) which acts as a pivot for the locking member and one end (57) of the connecting member is cranked to engage in a recess (48) of the locking member. The other end of the connecting member is shaped such that when engaged by the handle, as the handle is pivoted to retract the bolt, it transmits a force to said end (57) at the locking member to overcome the force of a spring (65) holding the locking member against the bolt, thereby to release the deadlocking and allow bolt retraction.