A safety mechanism for a hedge trimmer is disclosed. Thumb catches 1032, 1048, together with corresponding locking members are initially biased downwardly relative to corresponding actuator levers 1010, 1014, as a result of which actuation of a motor of the hedge trimmer is prevented. This prevents inadvertent one-handed actuation of the hedge trimmer. In order to actuate the hedge trimmer, the user holds one of the actuator levers 1010, 1014 the corresponding thumb catch 1032 or 1048 upwardly, which causes movement of the other thumb catch towards its release position to allow pivotable movement of the actuator levers 1010, 1014 relative to a handle of the hedge trimmer. Movement of one of the actuator levers 1010, 1014 relative to the handle brings the lever 1018 into engagement with the electrical switch assembly 1008 to actuate the motor of the hedge trimmer. When the actuator levers 1010, 1014 are released, torsion springs urge the actuator levers 1010, 1014 and locking members outwardly relative to the handle housing 1004, as a result of which the locking members are urged into a locking position to prevent further actuation of actuator levers 1010, 1014 until the thumb catches 1032, 1048 have again been slid out of their locking position.