They may vacate office by replacement or resignation or by ceasing to be a member of the House to which they belong. Here the President has no discretionary power. The President acting on the advice of the Prime Minister, may assign to the Prime Minister or any other Minister responsibility for any business of the government including the administration of any department of government. The responsibilities so allocated to Ministers are detailed in their letters of appointment. A Minister assigned responsibility for any department of government exercises general direction and control over that department and is answerable to Parliament for that department's activities.
Ministers normally decide all matters within their responsibility.
However on important political matters, they usually consult their colleagues collectively either through Cabinet or a Cabinet Committee. In addition to the members of the Cabinet, the President may appoint, on the advice of the Prime Minister any number of Parliamentary Secretaries from among Senators and members of the House of Representatives. The functions of Parliamentary Secretaries are to assist Ministers in the performance of their duties. The Constitutions provides for a Director of Public Prosecutions - a public office. To take over and continue any such criminal proceedings that may have been instituted by any other person or authority.