Elections and voting
How are Members of Parliament elected to the House of Commons in general elections and by-elections?
What does the dissolution of Parliament mean for the House of Commons and the House of Lords? Why do MPs and members of the Lords take an oath of allegiance before they take their seats?
A general election is an opportunity for people in every part of the UK to choose their MP - the person who will represent their local area (constituency) in the House of Commons for up to five years.
A by-election occurs when a seat in the House of Commons becomes vacant between general elections, because the sitting MP dies, resigns or becomes ineligible to sit for some other reason.
The United Kingdom is currently divided into 650 parliamentary constituencies, each of which is represented by one Member of Parliament in the House of Commons.
Members of both the Commons and Lords have to take an oath of allegiance to the Crown when they take their seat in Parliament, or after the death of the monarch.
The House of Commons, devolved assemblies and mayors in the UK are elected using different voting systems. The Commons and the Lords also use a variety of voting systems for internal elections.