Should we trust the exit poll? In some ways it is the most accurate of all the polls before the final result is announced early on Friday morning, because it tells us how people have voted rather than how they will vote.
However considering it is so different from most pre-election polls, many are questioning its accuracy and YouGov said it found no reason to change its final prediction before polling day, which put the Tories on 284, Labour on 263, Lib Dems on 31 and the SNP on 48.
Lord Ashcroft meanwhile has also put the result much closer, with his post-vote poll of a sample of 12,000 putting the Conservatives on 34 per cent and Labour on 31 per cent.
Vote shares in my 12,000 sample post-vote poll: CON 34%, LAB 31%, LDEM 9%, UKIP 14%, GRN 5%, SNP 5%, Others 2%— Lord Ashcroft (@LordAshcroft) May 7, 2015
So how does the exit poll work? This year it is conducted jointly for the BBC, ITN and Sky and uses surveys of roughly 20,000 people to tell us how the nation has voted.
It is conducted by 140 researchers at 140 polling stations across the UK, with venues chosen that are seen to be representative of the constituency they are in.
Results are sent in to a central team of five pollsters, who use the data to generate a national prediction.
In 2010 the exit poll was very accurate, under-predicting Labour’s seat share by three and over-predicting the Liberal Democrats by two.
But in 1992 the two exit polls for ITN and BBC wrongly predicted a hung Parliament - John Major had just about secured a majority for the Conservatives.
In pictures: Experts' predictions for the General Election - 03/05/15
In pictures: Experts' predictions for the General Election - 03/05/15
1/10 Andrew Hawkins (ComRes)
“The sclerotic, negative and risk-averse campaigns from the two main parties make it hard to see how much can alter. So, my prediction is the same – Tories get most votes, but Labour better placed to form a government. Then a long spell of political and perhaps constitutional chaos.”
2/10 Joe Twyman (YouGov)
“‘The world is changed, I feel it in the water, I feel it in the earth. I smell it in the air.’ So begins the film version of Lord of the Rings. – which is, of course, the famous tale of an epic journey culminating in the final battle between good and evil. The world of British politics has certainly changed. “With a few days still to go I expect that more change could still occur, but it is likely to be minor and the national level and more concentrated on the ground in the key marginal constituencies where the Hold Your Nose or Cut It Off to Spite Your Face™ message pushes home. I expect the Conservatives to be the beneficiaries, but it will not be anything like enough to make a difference to the overall result.”
3/10 Ben Page (Ipsos MORI)
“As the only pollster to correctly predict a hung parliament last time – and then foolishly change my prediction when I saw ALL the others were saying a Conservative majority – I am going to say hung parliament again. With more Conservative than Labour seats. The SNP won’t wipe out the Labour Party completely in Scotland but will get them down to single figures. The Lib Dems will out perform their poll numbers and should get circa 26 seats – or more. Ukip will be delighted with four seats at most, probably fewer.”
4/10 Rick Nye (Populus)
“Tories largest party, comfortably.”
5/10 Nick Moon (GfK)
“SNP now 50, Ukip 2; Tories to be largest party in votes and seats, but still a Labour minority government.”
6/10 Damian Lyons Lowe (Survation)
“Conservatives – I’m upgrading my seats prediction to 270-280 from 260-280. Labour – downgrading again to 265-275, based on the SNPs’ continued surge and Conservatives doing better in our seat-voting question as the election draws near and views are localised: SNP 45; Lib Dems 30; Ukip 6; Green 1; Respect 1. Ed Miliband will be the next prime minister.”
7/10 Michelle Harrison (TNS)
“We enter the last few days of this campaign pretty much where we started. This election represents what happens when a country is not confident about its economic future, unsure of its place in the world, and fed up with the state of its politics. “The political stalemate at the centre, and the fragmentation of the traditional party system, has left us with a set of polls incapable of telling what will ultimately happen, when there are so many potential scenarios. What we can feel confident about though is that Thursday will be a seismic night for politics in Scotland. When the votes are counted, we expect the Tories to be the largest party, but that Labour should still have the greatest chance of forming a government. But how do we measure the advantage for the Conservatives of already being in No 10 in the days after the general election? The real drama will start on Friday.”
8/10 James Endersby (Opinium Research)
“We saw some movement to the Tories, but the two big parties are back to being neck and neck with the Conservatives a hair’s breadth ahead. How this translates into seats or a coalition is unclear but based on our numbers we’d put the Conservatives ahead of Labour on vote share but the two parties within 10 seats of each other in the new House of Commons. The maths here gives Ed Miliband more options than David Cameron, so it might be sensible for voters to look up Ramsay MacDonald when trying to make sense of the result!”
9/10 Martin Boon (ICM)
“The Tories appear to have developed a little momentum, which may or may not make any difference. I sense the now traditional herding of pollsters has begun, and the polls will coalesce around a Tory lead of between two and six points. I’ll guess at 36 per cent for the Tories and 32 per cent for Labour. The fight for third place could go either way. Beyond that I just don’t know what will happen and defer to the academics and gamblers when it comes to seat projections, and indeed when it comes to who on earth is going to form our next government. I’d like to apologise to Independent on Sunday readers for fence-sitting, but as I’ve said repeatedly of late: How should I know? I’m only a pollster.”
10/10 Lord Ashcroft (Lord Ashcroft Polls)
He refuses to make predictions. “My polls are snapshots, not predictions.”
It could have been even worse for the BBC, had it not made a last-minute adjustment before David Dimbleby addressed the nation. Minutes before 10pm it was predicting a Labour majority.
This election could see a repeat of 1992 as the rise of smaller parties make it much more complicated to predict how some of the most marginal constituencies will swing.
Stay up to date with all the latest election developments as the results roll in with our live-blog.
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