David Cameron on course for second term as premier
Exit poll puts Tories ahead but without overall majority
The Conservatives are set to be the largest party in the Commons but just short of a majority, according to the general election exit poll last night.
The exit poll put the Conservatives ahead on 316 seats, with Labour on 239 seats, the Liberal Democrats on 10, the SNP on 58 and Ukip on two as counting began across the country.
If borne out by results, it would leave the Tories 10 seats short of an overall majority but ahead of its result in 2010 - and stand far apart from all pre-election surveys.
Labour would be down 19 seats on their result last time as the SNP were forecast to make sweeping gains of all but one Scottish seat.
DUP votes might then be crucial in forming the next Government.
If the results prove correct it would be a huge blow for all of the established pollsters, none of whom forecast a result close to that indicated by the exit poll.
YouGov chairman Peter Kellner said "everyone is puzzled" by the exit poll.
He told the BBC: "There are four possibilities. The first is that the exit poll is right and all the polls that came out in the last 24 hours, all 11 showed Conservatives and Labour neck and neck.
"The second possibility is the exit poll is wrong, the eve of poll polls were right. Third possibility is something happened today. We interviewed 6,000 people today and found no sign of any movement in any direction, so I think we can rule out an on the day shift.
"The fourth possibility is it is somewhere in the middle, the Tories have done a bit better than the eve of poll polls, and Labour did less well." In a separate survey released after the polls closed, YouGov published results closer to those on offer before polling day.
Based on interviews with 6,000 people after they voted, it found the Tories and Labour tied on 34%, with Ukip on 12%, Lib Dems 10% and the SNP and Plaid both on 5%.
Mr Kellner told the Sun, who commissioned the poll, the numbers from the final YouGov poll endorsed his earlier prediction of 284 MPs for David Cameron, with Ed Miliband on 263, Nick Clegg's Lib Dems 31, the SNP 48, Ukip two, Plaid Cymru three, and the Greens on one.
The SNP also advised the exit poll result be treated with caution.
Ms Sturgeon tweeted: "I'd treat the exit poll with Huge caution. I'm hoping for a good night but I think 58 seats is unlikely."
Derek Mackay, transport minister and SNP business convenor, told the BBC: "Talk about managing expectations... I think the SNP is probably going to have quite a good night. But 58 feels somewhat high on the optimistic side."
Labour deputy leader Harriet Harman also urged caution over the poll, saying: "I have been on television where I have been commenting on exit polls in the past where the exit polls were wrong, because it is difficult to read these situations from exit polls."
Asked if Mr Miliband could continue as leader if the poll proved correct, she said: "Well, at this stage we are just waiting for the counts and seeing whether or not David Cameron has got a House of Commons voted in which is prepared to give him a majority. You will forgive me for actually waiting until we have the answer to that big question before we go on to any other hypotheticals."
Ms Harman told Sky News that Labour were sceptical of the exit poll but if it was borne out, it showed the coalition had lost its majority.
She said: "We will have to see the actual results. We absolutely know from going around the country that people are very concerned about their family finances and the cost of living and very worried about the NHS.
"If it is the case David Cameron has lost a majority for his coalition, then that would not surprise me at all. But I am very sceptical about that exit poll."
Ukip deputy leader Paul Nuttall expressed severe doubts over the accuracy of the exit poll, and said the party was "buoyant and confident" that it would win more than two seats.
"The feeling that we are getting on the ground is that it's pretty tight between the Conservatives and Labour," he said.
Nigel Farage was on course to win in South Thanet, and by a larger margin than expected, and the party appeared to have performed strongly in Kent, Essex and elsewhere, Mr Nuttall suggested.
Psephologist Professor John Curtice of Strathclyde University, who led the exit poll operations, said that around 22,000 voters had been questioned at 141 polling stations.
The locations used were the same as in 2010, when the exit poll provoked surprise on its announcement, but turned out to be extremely accurate.