The United Kingdom is a constitutional monarchy and a parliamentary democracy. The other chamber, the House of Lords, has limited legislative powers. The members of the House of Commons are elected from specific geographic constituencies, each representing about 60,000 voters. The government is formed by whichever party, or coalition of parties, can command a majority in the Commons.
Legislation is passed by majority vote.
Right now, the major parties are the ruling Labour Party and the Conservative Party. The Liberal Democrats constitute the only other significant political force. The prime minister, who is the leader of the majority party, or coalition of parties, in the House of Commons, is the head of government. Tony Blair has held the position of prime minister since May 1997. Because of his party affiliation, the UK's government is currently a Labour Party government.