Whenever the Prime Minister is ill, absent from Singapore, or has been granted leave of absence from his duties, the functions conferred on him by the Constitution are exercisable by any other Minister authorized by the President. In general, the President must act in accordance with the Prime Minister's advice in appointing a Minister for this purpose. However, the President may act in his own discretion if in his opinion it is impracticable to obtain the advice of the Prime Minister due to his illness or absence.