A vehicle having: a prime mover; first and second groups of wheels; and a driveline operable by a controller to connect the first group of wheels to a torque transmission path when the driveline is in a first mode, and the first and second groups of wheels thereto when in a second mode. The driveline is operable to connect the second group of wheels to the torque transmission path via an auxiliary portion comprising first and second releasable torque transmitting means and a prop shaft, the first and second torque transmitting means are respectively operable to connect the prop shaft to the torque transmission path and the second group of wheels. The controller is operable to control the driveline to transition from the first mode to the second mode at a connect rate that is responsive to the identity of a trigger condition that is met.