49.5 million people are registered to cast their votes in the UK general election on Thursday 7 May. Polls open at 07:00 BST at around 50,000 polling stations across the United Kingdom. A total of 650 Westminster MPs will be elected, with about 50 million people registered to vote.
As well as the general election, there are more than 9,000 council seats being contested across 279 English local authorities. Mayors will also be elected in Bedford, Copeland, Leicester, Mansfield, Middlesbrough and Torbay.
This means that nearly every voter in England - excluding London where there are no local elections - will be given at least two ballot papers when they enter polling stations.
Some votes have already been cast, through postal voting, which accounted for 15% of the total electorate at the 2010 general election, when the overall turnout was 65%. For the first time, people have been able to register to vote online.
Most polling stations are in schools, community centers and parish halls, but pubs, a launderette and a school bus will also be used. A handful of seats are expected to be declared by midnight, with the final results expected on Friday afternoon.
Polls close at 22:00 BST, but officials say anyone in a polling station queue at this time should be able to cast their vote. The BBC's main election program, fronted by David Dimbleby, starts at 21:55 BST, with live coverage from 220 counts.
Wales, Scotland and Northern Ireland will have their own overnight programs but will join Huw Edwards from 07:00 BST on 8 May. On the radio, a joint overnight broadcast by BBC Radio 4 and 5 live will be hosted by Jim Naughtie and Carolyn Quinn.
Full coverage of the results as they come in will be on the BBC politics online live page and front page scorecard, with all the big breaking stories from around the country and analysis by correspondents.