The Cabinet is appointed by the Prime Minister. The senior positions within the Cabinet are usually appointed by the Prime Minister within hours of an election victory. In British Politics, all Cabinet members are serving MP's or peers though in the recent past, Tony Blair has experimented with allowing non-party politicians into Cabinet meetings - most notably Paddy Ashdown who lead the Liberal Democrats immediately after the 1997 election.
The most senior members of the Cabinet are the Deputy Prime Minister, Foreign Secretary, Chancellor of the Exchequer and Home Secretary. These positions are the ones most immediately made known after the result of a general election is known. 'Lesser' posts are announced later and it may be a day or two before the minor Cabinet positions are made known.
There has never been a set number for posts within the Cabinet. The Prime Minister can amalgamate government departments and join together Cabinet positions and he can also create new ones thus requiring a new Cabinet post. The most common figure for a Cabinet is 22. The current Labour Cabinet numbers 24.
Unlike the American version, heads of government departments are not usually experts in their fields. Hence they are surrounded by experts from the Civil Service and what are referred to as 'special advisors'. The current Cabinet members who buck this trend are Gordon Brown who is considered to be highly skilled in economic matters and Estelle Morris, who as Minister for Education, has a teaching background. In America, heads of government departments are selected for their expertise within their fields and they do not have to be serving politicians to be appointed by the president.
In theory, Britain has a Cabinet government. This according to current constitutional theory, is where the Cabinet meets as a body to discuss issues relevant to the country. It discusses various points of view, weighs up arguments concerning whatever is being discussed and comes to a decision that is backed by the majority of the Cabinet. As such it becomes government policy, if supported in the House of Commons, and has the legitimacy of majority Cabinet support behind it. This means that decisions have collective responsibility behind them - all Cabinet members would be expected to publicly support and defend such policies. Cabinet ministers would also be expected to defend such policies during Parliamentary debates. If a Cabinet minister feels that he/she cannot defend a policy, he/she has the option to resign from the Cabinet. The most high profile Cabinet Minister to do this in recent years was Michael Heseltine who quit Thatcher's Cabinet in 1986 over the Westland helicopter affair. However, Tony Blair has been accused by some of moving away from cabinet government to prime ministerial government and of by-passing his Cabinet in favour of decision making by a few favoured individuals.
The Cabinet has no official standing in itself. It acts through the Privy Council. The Privy Council dates back to the C13th and contains several hundred people including Cabinet ministers, former Cabinet ministers, the Speaker of the House, the Lords of Appeal etc. It only meets when the monarch dies or decides to marry. When this is not happening, its business is conducted by the Cabinet. Therefore all members of a government Cabinet are members of the Privy Council.
There are limits to the power of people who serve in a Cabinet. People appointed to it can be dismissed by the Prime Minister; in an age of supposedly prime ministerial government, the impact of the Cabinet may be less and less; the Prime Minister drives the agenda of Cabinet meetings so that contentious issues can be left out of discussion and the Cabinet can do little if the Prime Minister does prefer to use a 'kitchen cabinet'. Also a Cabinet minister must take full responsibility for any problems that occur that involve his/her department. The serious problems with trains lead to the resignation of Stephen Byers, Minister of Transport, in 2002 to be replaced by Alastair Darling. In such a fall from political grace, cabinet privileges are lost immediately as the politician involved returns to the back- benches.