Abstract: A vehicle roll control system (22,24) for a vehicle (10) having a pair of wheels (12,16) each rotatable on an axle (14,18), comprising a torsion bar (26); a first arm (28) extending substantially perpendicular to the torsion bar, the first arm being fixed to the torsion bar at one end and being connectable to one of the axles at the other end; a second arm (30) extending substantially perpendicular to the torsion bar, the second arm being rotatably mounted on the torsion bar at one end and being connectable to the other axle at the other end; and an actuation (32,34) connected between the second arm and the torsion bar, the actuation being actuable on detection of a predetermined vehicle condition to substantially prevent or allow rotation of the second arm relative to the torsion bar.