An electrosurgical instrument includes a housing including an elongated shaft. A stationary actuation member is axially disposed within the elongated shaft and includes a cam pin. An actuating mechanism is operably coupled to the elongated shaft and is moveable relative to the housing to selectively cause movement of the elongated shaft. An end effector includes a pair of opposing first and second jaw members operably coupled about a common pivot. One or both of the jaw members includes a camming slot configured to engage the cam pin. Each jaw member includes an electrically conductive tissue sealing surface adapted to connect to a source of electrosurgical energy. A knife blade is supported in the elongated shaft and moveable in a longitudinal direction to cut tissue disposed between the jaw members. A switch is configured to be engaged by the actuating mechanism to initiate delivery of electrosurgical energy to tissue.