Pruning shears include a cutting head with a spring-biased blade pivotally connected to a jaw and arranged to sever a workpiece received in a bight formed by the jaw. A drive mechanism is connected to the cutting head and an elongate housing is connected to the drive mechanism. The drive mechanism includes a rotation preventer for preventing rotation of a second pulley in relation to the drive mechanism when a drawing torque is applied to the second pulley. The drawing torque is greater than a threshold torque, resulting in a second pulley being stationary in relation to the drive mechanism and the first pulley rotating in relation to the drive mechanism.