Power system load shedding has been used as an emergency control method to prevent possible power system instability problems. In this paper, a new multi-stage model predictive control based load shedding scheme is proposed to enhance long term voltage stability of a power system. The main advantage of this new method is the capability of the scheme to handle multi-stage control actions, which may also be disturbances to a power system at a critical status toward instability. A new cost function is defined for the model predictive control scheme. The proposed scheme is tested on the New England 39-bus system to validate its efficiency and effectiveness in preventing system long term voltage stability problems.