The United Kingdom of Great Britain and Northern Ireland is a constitutional monarchy.The power of Queen Elizabeth II is not absolute. It is limited by Parliament. The legislative body, Parliament, consists of two chambers: the House of Lords and the House of Commons.The executive body consists of the central Government — that is the Prime Minister and the Cabinet of Ministers, who are responsible for initiating and directing the national policy.The judiciary body is independent of both the legislative and the executive ones.The Government derives its authority from the elected House of Commons. General elections, for all seats in the House of Commons, must be held at least every five years. The Government is normally formed by the political party which is supported by the majority in the House of Commons. The leader of the party is appointed the Prime Minister by the Queen and chooses a team of ministers. The second largest party becomes the Official Opposition with its own leader and the “Shadow Cabinet”.The House of Lords is a hereditary chamber.In Great Britain there is no written constitution, only customs and traditions.