An apparatus for application of surgical clips to body tissue, the apparatus comprising: a) a handle assembly; b) a shaft assembly extending distally from the handle assembly and defining a longitudinal axis, the shaft assembly including an upper and a lower housing disposed within a lumen of an outer tube; c) a plurality of surgical clips disposed within the shaft assembly; d) jaws mounted adjacent a distal end portion of the shaft assembly, the jaws including a pair of jaw members movable between a spaced-apart and a approximated position; e) a clip pusher bar configured to individually distally advance a surgical clip to the jaws while the jaw members are in the spaced apart position. f) a drive bar at least partially disposed within the handle assembly and the shaft assembly, the drive bar being longitudinally movable in response to actuation of a trigger of the handle assembly; g) a drive channel positioned adjacent the first and second jaw members to move the jaw members to the approximated position; and h) a lockout system configured to selectively engage the clip pusher bar, characterised in that i) the lockout system comprises a lock-out bar supported in the shaft assembly, the lock-out bar being pivotally supported in a channel of the upper housing, and including a biasing member securely connected within the channel of the housing and operatively connected to the lock-out bar so as to bias the lock-out bar to force the lock out bar radially outward away from the lower housing and wherein the lock-out bar is configured to selectively engage and extend through a window formed in a distal region of the clip pusher bar to prevent the clip pusher bar from returning to a home position and to prevent the trigger from completing a full stroke when the plurality of clips are substantially exhausted. a) a handle assembly; b) a shaft assembly extending distally from the handle assembly and defining a longitudinal axis, the shaft assembly including an upper and a lower housing disposed within a lumen of an outer tube; c) a plurality of surgical clips disposed within the shaft assembly; d) jaws mounted adjacent a distal end portion of the shaft assembly, the jaws including a pair of jaw members movable between a spaced-apart and a approximated position; e) a clip pusher bar configured to individually distally advance a surgical clip to the jaws while the jaw members are in the spaced apart position. f) a drive bar at least partially disposed within the handle assembly and the shaft assembly, the drive bar being longitudinally movable in response to actuation of a trigger of the handle assembly; g) a drive channel positioned adjacent the first and second jaw members to move the jaw members to the approximated position; and h) a lockout system configured to selectively engage the clip pusher bar, characterised in that i) the lockout system comprises a lock-out bar supported in the shaft assembly, the lock-out bar being pivotally supported in a channel of the upper housing, and including a biasing member securely connected within the channel of the housing and operatively connected to the lock-out bar so as to bias the lock-out bar to force the lock out bar radially outward away from the lower housing and wherein the lock-out bar is configured to selectively engage and extend through a window formed in a distal region of the clip pusher bar to prevent the clip pusher bar from returning to a home position and to prevent the trigger from completing a full stroke when the plurality of clips are substantially exhausted.