No-one can predict the outcome of the General Election 2015 with complete certainty, but with less than 24 hours until the result, there are a number of factors to take into account when trying to work out what will happen.
What the polls say
Over the campaign period there have been many, many polls. Three on Wednesday put Labour and the Tories neck-and-neck on the eve of the election - a result a polling company concluded is "too close to call".
A Guardian/ICM poll had the parties tied at 35% while a YouGov poll also put both parties on 34%. TNS has the Conservatives marginally ahead on 33% to Labour's 32%, each down one point, and within the "margin of error" according to the pollster.
The 'poll of polls' on the election website May 2015, from the New Statesman, charts the ratings from the major polls such as Lord Ashcroft, ICM and ComRes. It shows just how close the Conservatives and Labour have been throughout the campaign.
While the Tories were doing better in polls at the end of 2014, the 'poll of polls' shows Labour on a slight upward trajectory - momentum that, if it continues at the ballot box, could see Labour take a narrow lead.
But what the polls could well point to, according to Michelle Harrison, head of political and social at TNS, is the possibility that there is no winner, and no party secures overall majority. The question then would be "whether the party with the most seats or the biggest share of the vote can claim the greatest legitimacy in forming the next government," she said.
What the bookies say
The bookies' odds will be changing up until the results are called and a new government is formed, but at 7pm the night before the election, Paddy Power's best odds was that there would be a Labour minority government. This means that Labour would win the most seats, but not enough to have a majority in Parliament.
The odds on this, at 7pm on Wednesday, were 2/1 - so you'd still double your money if you put a bet on that outcome. The second most likely "winners" according to the bookmaker would be a Conservative and Lib Dem coalition returning to power, with odds of 9/4.
Odds from rival bookie Betfair, also on Wednesday evening, confirmed the same two combinations as the most likely outcomes.
What logic says
Logic tells us that, whatever happens, this is the closest election in decades. Whichever party "wins", if that term even applies to the outcome, they are highly unlikely to have a majority: it will most likely be a hung parliament. So the only prediction we can perhaps make, with some confidence, is that no-one will win. The negotiations after the election results could be long and more complex than the discussions for the coalition of 2010 - which were already the first of their kind in recent history.
GENERAL ELECTION 2015