An electrosurgical apparatus comprising an electrosurgical forceps instrument that combines a robust jaw opening mechanism with an microwave energy delivery mechanism. The instrument includes a rigid bracket mounted at a distal end of a flexible shaft, wherein a pair of jaws are pivotably mounted on the rigid bracket. The instrument includes an energy delivery structure comprising a flexible dielectric substrate having a first electrode and an second electrode formed on one of the pair of jaws, wherein the first electrode and the second electrode are arranged to emit microwave energy. The electrosurgical apparatus may also comprise a handpiece that combines rotation control of an electrosurgical instrument with both power delivery and end effector actuation (e.g. jaw closure, blade retraction or the like).