Key facts about Britain's electoral process.
VOTING POPULATION
Everybody over the age of 18, barring prisoners, peers and members of the Royal Family, is eligible to vote. The National Statistics Agency says 44.9 million people are registered on the electoral role. The total population is 59.6 million.
FIRST PAST THE POST SYSTEM
There are 659 constituencies in Britain which each directly elect one member of parliament. There is no form of proportional representation. The candidate with the most votes in each seat wins, often with less than 50 per cent.
As a result Britain rarely sees coalition government, something which is the norm in many of its European partner countries.
1997 RESULT
In the outgoing parliament the ruling Labour Party holds 417 seats, giving it a majority of 179. In 1997, Labour won 43.2 per cent of the vote, the Conservatives 30.7 and the Liberal Democrats 16.8 per cent.
TURNOUT
In 1997, 71.6 per cent of the voting population exercised their right. That figure is expected to fall this time.
ELECTION DAY
On election day, polling booths are open for business from 6 a.m. GMT and will close at 9 p.m. (both GMT) Counting takes place in each constituency. Exit polls by the two main terrestrial television networks give a good clue to the result soon after the polls close.
The official result comes many hours later, generally when one of the main party leaders concedes defeat.