The Executive Government in Australia is defined by Chapter 2 of the Constitution.
According to the Constitution, the executive power of the Commonwealth is vested in the Queen and is exercisable by the Governor-General.
The Governor-General is provided with an Executive Council to advise him in the government of the Commonwealth. According to Section 64, the executive councillors hold office at the pleasure of the Governor-General.
In practice, the Governor-General simply acts on the advice of the ministers of the day who comprise the Executive Council, although on one notable occasion in 1975 this did not occur and the Whitlam Government was dismissed.
In practice, the executive power is exercised by the ministers in the government. These ministers are chosen by a Prime Minister who is the leader of the party or parties that command a majority in the House of Representatives, the lower house.
The Constitution makes no mention of a Cabinet as such, although it does refer to the Governor-General’s advisers and ministers of State. Much of the operation of the Cabinet derives from conventions that have developed over time and which arose from the British Westminster system of government.
The most important principles of Cabinet Government require the ministers to speak collectively with one voice and to accept responsibility for the actions of their departments.
The ministers are divided into two groups, with the most senior ministers taking responsibility for the major areas of government policy, such as Treasury, Defence, Foreign Affairs, Health, etc. These ministers comprise the Cabinet and are led by the Prime Minister.
There are 18 members of the Howard Cabinet, with a further 13 ministers making up what is often referred to as the outer ministry. All members of the ministry and cabinet must be members of parliament and may come from either the House of Representatives or the Senate.
Ministers act as the political heads of government departments and are responsible for the administration of those departments, as well as the development and implementation of government policy. The ministers are bound by conventions of collective and individual ministerial responsibility.