An electrical data connector comprising a plug that is configured for insertion in a longitudinal direction into a complementary receptacle said plug including a connector element with a first end and a second end, wherein the first end of the connector element is configured to be received within the receptacle and carries a plurality of electrical connectors, a body that is connected to the second end of the connector element , and a releasable locking mechanism for locking the plug positively to the receptacle to prevent unintentional removal of the plug from the receptacle , wherein the locking mechanism includes: a. a locking element carried by the connector that is configured for movement between a locked configuration in which it protrudes from the connector element and an unlocked configuration in which it does not protrude substantially from the connector element ; b. a manual locking control , provided on the body , for manually actuating the locking mechanism , and c. a drive mechanism that connects the manual locking control to the locking element , whereby operation of the manual locking control actuates the locking element ; wherein the drive mechanism includes at least one longitudinal sliding element that is connected to the manual locking control and at least one transverse sliding element that is connected to the locking element, wherein said longitudinal and transverse sliding elements are located in a common plane and are configured such that longitudinal movement of the longitudinal sliding element drives transverse movement of the transverse sliding element , thereby actuating the locking element , wherein the locking element comprises at least one pin that is rotatable about a longitudinal pivot axis, said pin including a crank portion at a first end that engages the transverse sliding element and a hook portion at a second end that extends substantially perpendicular to the longitudinal pivot axis, wherein the hook portion is rotatable between a locked position in which it protrudes from the connector element and an unlocked position in which it does not protrude substantially from the connector element (10, 110, 210 310); characterized in that the longitudinal sliding element comprises one cam surface which engages a respective cam surface of the transverse sliding element , whereby movement of the longitudinal sliding element in a first longitudinal direction drives movement of the transverse sliding element in a first transverse direction through the cam surface (28', 128', 228', 228") and wherein movement of the longitudinal sliding element in a second longitudinal direction drives movement of the transverse sliding element in a second transverse direction through a further cam surface (226") disposed at the longitudinal sliding element or through a pivoting element located in the common plane. a. a locking element carried by the connector that is configured for movement between a locked configuration in which it protrudes from the connector element and an unlocked configuration in which it does not protrude substantially from the connector element ; b. a manual locking control , provided on the body , for manually actuating the locking mechanism , and c. a drive mechanism that connects the manual locking control to the locking element , whereby operation of the manual locking control actuates the locking element ; <EOS>