The Prime Minister of the United Kingdom of Great Britain and Northern Ireland is the head of Her Majesty's Government in the United Kingdom. The Prime Minister (informal abbreviation: PM) and Cabinet (consisting of all the most senior ministers, who are government department heads) are collectively accountable for their policies and actions to the Monarch, to Parliament, to their political party and ultimately to the . The , David Cameron, leader of the Conservative Party, was appointed by the Queen on 11 May 2010.