The pm and cabinet are usually referred to as the govt of the day, as in the harper govt . The pm"s and cabinet"s functions and powers rest on custom and convention. W/ the rare exception of governors general intervening on their own discretion, the pm & cabinet exercise whatever powers are given to the queen or the governor general in the constitution. It is from this source that many decisions made by the cabinet take the form of orders in council. Thus after an election, the governor general calls on the leader of the party with the most members elected to the house of commons to become the pm and to form a govt. Leadership is based on the twin concepts of collective and individual ministerial responsibility. Beyond the powers of the crown and this general leadership function, cabinet power is derived from specific acts of parliament.