Millions of voters were going to the polls today in the most tightly-contested General Election in a generation.
Polling stations around the country opened at 7am and will close at 10pm - with the first results expected before midnight.
The three party leaders all cast their votes with Tory leader David Cameron voting first, accompanied by pregnant wife Samantha as they went to the polling station in Witney, Oxfordshire.
Mr Cameron's arrival was delayed by more than two hours after pranksters scaled the roof of the polling station.
Prime Minister Gordon Brown voted next in North Queensferry, with his wife Sarah.
Liberal Democrat leader Nick Clegg then cast his vote in Sheffield, accompanied by his wife Miriam Gonzalez Durantez, who cannot vote for her husband as she is a Spanish citizen.
There was election drama elsewhere as former Ukip leader Nigel Farage was hurt when a polling day stunt in a light aircraft went crashing to the ground.
The MEP and parliamentary candidate in Buckingham suffered facial injuries when the plane he was in towing a "Vote for your country - Vote Ukip" banner came down in Northamptonshire.
As voting continued, there was more genuine uncertainty about who would eventually emerge as Prime Minister than in any election since 1992 and a real expectation of a hung Parliament for the first time since 1974.
A string of eve-of-election opinion polls gave David Cameron's Conservatives a clear lead over Labour and the Liberal Democrats, but suggested that the Tories will not reach the level of support they need to claim an overall majority in the House of Commons.
After a frenetic final 48 hours of campaigning, which saw them criss-cross the country in a whirlwind of rallies and constituency visits, all three leaders last night issued appeals to activists to help get the vote out today.
Mr Cameron told cheering supporters in Bristol that it was time for the Tories to "win for Britain", urging them: "Get out tomorrow. Vote for change. Vote Conservative. Vote to give this country the hope, the optimism and the change we need. Together, we can build a better, stronger country."
Prime Minister Gordon Brown returned to Scotland, where he rounded off his campaign at a rally in Dumfries with a plea to wavering voters: "At this moment of risk to our economy, at this moment of decision for our country, I ask you to come home to Labour."
And Liberal Democrat leader Nick Clegg addressed a crowd of hundreds of people on the steps of Sheffield City Hall with an appeal for voters to "aim higher, don't settle for second best".
The final newspaper polls of the campaign all put Conservatives in the lead with support ranging between 35% and 37%. The other two parties were vying for second place, with Labour apparently edging slightly ahead on 28%-29% and the Liberal Democrats on 26%-28%.
On an even swing, the figures would make the Tories the largest party, with between 268 and 294 seats in the House of Commons, but leave them well short of the 326 MPs Mr Cameron needs to lead a majority administration.
The polls suggest Labour could emerge with around 248-274 MPs, with the Liberal Democrats holding the balance of power on 77-82 seats.
But much will depend on performance in individual constituencies, particularly the 100 or so Labour/Conservative marginals which hold the key to tonight's result and where the fiercest battles have been fought.
Strategists believe that an unusually large number of voters will only make their minds up when they get into the polling booths, adding an additional layer of uncertainty to the result.
If the Lib Dems suffer a classic last-minute "third party squeeze", with voters gravitating to the two larger parties, it could even have the effect of handing the balance of power to the Welsh and Scottish nationalists or the Northern Irish parties.
The Democratic Unionist Party last night claimed that they were being courted by Mr Brown ahead of a possible hung Parliament, releasing a letter in which the Labour leader promised to maintain the size of the block grant from Westminster to Northern Ireland if he remains in 10 Downing Street.
The national newspapers did their bit to boost the chances of their preferred candidates.
The Sun hailed Mr Cameron as "Our Only Hope" in a front-page echoing the famous campaign posters of Barack Obama, while the Daily Mirror painted a less flattering picture, asking "Prime Minister? Really?" alongside a picture of the Tory leader and a CV featuring his Eton education and support for fox hunting and listing his real-life experience as "None".
As well as the 650 MPs of the new Parliament, voters are also electing councillors in 166 local authorities across England - including London boroughs - and mayors in Hackney, Lewisham, Newham and Watford.Reuse content