A counterbalance mechanism for assisting in opening and closing of a closure panel of a vehicle between a closed position and an open position, the counterbalance mechanism including: a housing for mounting a biasing mechanism of the counterbalance mechanism between the body and the closure panel; the biasing mechanism including: a fixed primary abutment of the housing having a primary biasing element mounted thereon; a fixed secondary abutment of the housing having a secondary biasing element mounted thereon; a movable plate variably positioned on a bias axis, the moveable plate between the primary biasing element and the secondary biasing element, an axial position of the movable plate movable in relation to the fixed primary abutment and the fixed secondary abutment to selectively change a primary spring constant of the primary biasing element and a secondary spring constant of the secondary biasing element; and an actuator connected to the movable plate, the actuator responsive to a control signal in order to adjust the position of the movable plate; wherein the primary biasing element applies a spring force to moderate extension of the counterbalance mechanism affecting movement of the closure panel between the open and closed positions.