A flexible clip applier includes a flat wire wound outer tubular coil, a pair of jaws at the end of the coil, end effector wires extending through the coil and coupled to the jaws, and a clip-advancing wire extending through the coil. A large pushing force to advance a clip is created by providing a compressive force to the outer tubular coil to increase its tensile limitation, and providing a force which is compressive to the clip-advancing wire and tensile to the tubular coil while maintaining the compressive force on the tubular coil.