A forceps includes first and second shafts, each having a jaw member disposed at a distal end thereof. At least one jaw member is moveable from an open to a closed position for grasping tissue therebetween. At least one jaw member is configured for reciprocation of a blade therethrough. A trigger assembly includes a trigger and at least one linkage coupled to the trigger and to the blade such that rotation of the trigger translates the blade between the retracted and the extended position. An interference member moveable between a locked position and an unlocked position is also provided. The interference member is configured to engage the linkage(s) when in the locked position to inhibit translation of the blade from the retracted to the extended position.