<Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> <P> The Cabinet of the United Kingdom is the collective decision - making body of Her Majesty's Government of the United Kingdom, composed of the Prime Minister and 21 cabinet ministers, the most senior of the government ministers . </P> <P> Ministers of the Crown, and especially Cabinet ministers, are selected primarily from the elected members of House of Commons, and from the House of Lords, by the Prime Minister . Cabinet ministers are heads of government departments, mostly with the office of "Secretary of State for (function; e.g., Defence)". The collective co-ordinating function of the Cabinet is reinforced by the statutory position that all the Secretaries of State jointly hold the same office, and can exercise the same powers . </P> <P> The Cabinet is the ultimate decision - making body of the executive within the Westminster system of government in traditional constitutional theory . This interpretation was originally put across in the work of nineteenth century constitutionalists such as Walter Bagehot, who described the Cabinet as the "efficient secret" of the British political system in his book The English Constitution . The political and decision - making authority of the cabinet has been gradually reduced over the last several decades, with some claiming its role has been usurped by a "prime ministerial" government . In the modern political era, the Prime Minister releases information concerning Cabinet rank; a list detailing the seniority of all Cabinet ministers . </P>

In the british system a member of the cabinet is called