Elected Members of Parliament sit in the House of Commons. The House of Commons is the main and superior debating chamber of parliament. It is the centre of parliamentary power.

There are 659 MPs. They debate and vote on legislation (Bills) presented to the House by the government or individual members. They also study the work of the government through various committees.

Each week (Wednesdays), MPs question the Prime Minister on his policies and work.

The government can only remain in power if it has the support of the majority of the House of Commons.

All debates in Parliament are written down in a publication called Hansard. Proceedings are also available on radio and television.

The party that comes second in a general election is called the Opposition. In Parliament the government party sits on one side of the House of Commons. The other parties who have Members of Parliament sit opposite.

The Opposition challenges, opposes and questions the government on its policies and actions. The leader of the opposition is currently David Cameron.

The House of Lords consists of peers, law lords, archbishops and bishops. Member of the House of Lords are not elected. They discuss House of Commons legislation, debate issues of importance and question government ministers. The House of Lords is also the highest court in the United Kingdom.

Most Bills have to be approved by the House of Lords to be made law.

There were 689 members of the House of Lords in April 2003.

Members of the House of Lords are not paid, but receive money for expenses.

Each party has Whips (a bit like school prefects) who inform MPs and peers about parliamentary business, make sure they turn up for important debates and also that they support their party on crucial votes.

Devolution means that people in different areas of the UK can make decision for their own areas. It's an alternative to having decision made by politicians hundreds of miles away in London.

Wales, Scotland and Northern Ireland have their own parliaments or assemblies to look after national affairs as well as electing Members of Parliament. The Northern Ireland Assembly was suspended in 2002.