Abstract: An electrical connector assembly is disclosed which comprises first and second elements rotatable with one another and housing a conductor electrically connecting respective terminals provided on the first and second elements. A locking assembly is provided to restrict removal of the connector assembly from a support structure, the locking assembly including a locking member moveable in response to movement of the second element relative to the first element to and from a datum position such that the locking assembly permits removal or replacement of the connector assembly when the second element is in the datum position and prevent such removal or replacement when the second element does not occupy the datum position.