The present invention relates to a mechanical operating assembly for a bistable relay and a bistable relay assembly. The mechanical operating assembly comprises: an actuating mechanism mounted to a bracket, including an actuating member and a first transmitting member which is connected to a paddle, the actuating member is movable between an initial position in which the actuating member is not in contact with the first transmitting member and an actuating position, when the actuating member moves from the initial position to the actuating position, the actuating member contacts the first transmitting member; a reset mechanism mounted to the bracket, including a reset member and a second transmitting member which is in contact with the first transmitting member, the reset member is movable between an initial position and a reset position, the reset member contacts the second transmitting member when moving from the initial position to the reset position.