The lower house, the House of Commons, consists of MPs (Members of Parliament) elected from one of 646 electoral districts. The Speaker of the House of Commons, elected by the House, acts as the referee in debate between the majority and the minority.
The MPs in the House of Commons sit for five years, or until the monarch (at the Prime Minister's behest) dissolves Parliament and calls for new elections. In Britain, the majority party in the House of Commons holds all of the power. The House of Lords holds little more than delaying powers.
The following are the powers of the Legislature: Passes all federal laws; establishes all lower federal courts; can override a Presidential veto; can impeach the President.
The following are the powers of the Judiciary: the power to try federal cases and interpret the laws of the nation in those cases; the power to declare any law or executive act unconstitutional.
The President does not have veto power over legislation, but can ask Parliament to reconsider a bill.
The Prime Minister heads The Government, akin to the American Cabinet.
As of 2005, the very existence of the House of Lords is in question.
There are some calling for its abolition, but a combination elected/lifetime appointment system seems more likely. Since Britain has no formal, written constitution, no law can be unconstitutional.
The Executive, composed of the President, Vice-President, and the Departments, is set up in Article 2.
The Judicial, composed of the federal courts and the Supreme Court, is set up in Article 3.