The opinion polls have consistently presented us with three key messages during the election campaign. First, whereas five years ago the Conservatives enjoyed a seven-point lead over Labour, now the two parties are more or less neck and neck. Second, the Liberal Democrats have fallen back heavily from the 24% they enjoyed in 2010. Third, voters appear set to vote for parties other than these three in unprecedented numbers.

This means in turn that there are three key battlegrounds. The first comprises the seats the Conservatives won narrowly in 2010, doing so in most cases by defeating the incumbent Labour MP. They range from seats like Warwickshire North, where the Tory majority last time was just 54 votes, to one like South Ribble where the 5.4% swing Labour requires is above what most polls anticipate the party will achieve.

Which party emerges with most seats – and thus who might be better placed to be prime minister – will be determined by how many of these seats stay blue or are turned red. Tory hopes in many of these rest on the belief that the swing against the party will be lower than it is nationally because many a first term Tory MP will pick up a personal vote as a result of their assiduous efforts during the last five years as constituency MPs.

The experience of first term MPs at other recent elections suggest that expectation may well be right – creating the paradox that who governs Britain could be decided by how voters in marginal seats have reacted to the personal performance of their local MP.

The apparent collapse in the Liberal Democrat vote defines our second battleground – seats the party is trying to defend. The party’s task seems most difficult in those seats, such as Burnley, where the party is trying to head off a Labour challenge. Labour itself is more popular than five years ago, while voters in such seats often appear particularly unforgiving of the Liberal Democrats’ involvement in the coalition.

In pictures: Experts' predictions for the General Election - 03/05/15 Show all 10 1 /10 In pictures: Experts' predictions for the General Election - 03/05/15 In pictures: Experts' predictions for the General Election - 03/05/15 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.” Andrew Hawkins In pictures: Experts' predictions for the General Election - 03/05/15 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.” In pictures: Experts' predictions for the General Election - 03/05/15 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.” In pictures: Experts' predictions for the General Election - 03/05/15 Rick Nye (Populus) “Tories largest party, comfortably.” In pictures: Experts' predictions for the General Election - 03/05/15 Nick Moon (GfK) “SNP now 50, Ukip 2; Tories to be largest party in votes and seats, but still a Labour minority government.” In pictures: Experts' predictions for the General Election - 03/05/15 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.” In pictures: Experts' predictions for the General Election - 03/05/15 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.” In pictures: Experts' predictions for the General Election - 03/05/15 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!” In pictures: Experts' predictions for the General Election - 03/05/15 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.” In pictures: Experts' predictions for the General Election - 03/05/15 Lord Ashcroft (Lord Ashcroft Polls) He refuses to make predictions. “My polls are snapshots, not predictions.” Rex

Even so, the Conservatives are enviously eyeing the 38 Liberal Democrat seats in which they start off in second place, as wining half or so of them potentially provides David Cameron with an alternative route to an overall majority. The Liberal Democrats believe the local popularity of many of their MPs will enable them to withstand the adverse electoral tide. That makes the outcome in traditional Liberal seats such as North Devon vital for both parties.

Finally, but by no means least, are the seats the “insurgents” hope to win. In the case of the SNP this means more or less the whole of Scotland - even Gordon Brown’s former Kirkcaldy and Cowdenbeath seat is apparently not safe. The better the nationalists do, the more fraught and contentious the process of forming a government is likely to be. At the same time, Nigel Farage has staked his future as Ukip leader on winning Thanet South while the Greens have their eye on Bristol West.

Still, at least we – and they - will all know their fates by tomorrow.