The functions of the Cabinet are policy making, the supreme control of government and the coordination of government departments. The Cabinet, therefore has two main roles; to propose legislation and to supervise administration.

Full meetings of the Cabinet usually take place once or twice a week, each only taking a maximum of two hours in duration. It is therefore not feasible for the full Cabinet to carry out detailed policy making over all areas covered by government policy. The Cabinet's dual role rests upon the party system. The outcome of elections determines the party balance in the Commons, and therefore which party or parties forms the government. The government then has a duty to implement party policy as presented in its election manifesto, the Cabinet's policy-making role clearly has a party political dimension. The Cabinet also depends on party support in the House of Commons for its continued existence.