Embodiments of the present invention provide a controller for a vehicle having a powertrain comprising an engine, the controller being operable to: receive a signal indicative of an amount of powertrain drive torque required to be applied to one or more wheels, powertrain wheel drive torque demand; and receive a signal indicative of an amount of powertrain load torque required to support an auxiliary powertrain load, powertrain auxiliary load torque demand, that is in addition to the powertrain wheel drive torque demand, the controller being operable to limit the amount of powertrain drive torque available to the one or more wheels and to limit the amount of powertrain load torque available to support the auxiliary load such that when a sum of the amount of powertrain wheel drive torque demand and the amount of auxiliary load torque demand exceeds the available powertrain torque, the one or more auxiliary loads may still receive at least a prescribed minimum auxiliary load powertrain torque amount.