LONDON - Britain's political leaders on Tuesday began a final push for votes ahead of Thursday's knife-edge election, even as they prepared for the likelihood of protracted coalition talks once polls close.
Conservative Prime Minister David Cameron, whose party is running neck and neck with the opposition Labour party in the opinion polls, kicked off a 36-hour tour of the country that will see him campaign through the night.
He urged people to give his party a clear mandate to govern or face years of "back-room deals" and "bribes" as Labour sought to form a government with the support of the smaller Scottish National Party (SNP).
But Cameron himself faces an uphill struggle to win enough seats in the House of Commons to govern alone and would most likely also need to turn to smaller parties to stay in power.
Both Cameron and Labour leader Ed Miliband - who is basing his final election push on a warning about funding for the state-run National Health Service (NHS) - have insisted they are aiming for a parliamentary majority.
In reality, all sides are planning how they will seize the initiative on Friday morning after an uncertain result.
Liberal Democrat leader Nick Clegg, whose centrist party has been the junior partner in Cameron's Tory-led coalition for the past five years, is keeping his options open.
Launching a tour in Land's End in southwest England that will end in John O'Groats in northern Scotland, Clegg said he would support the party with the "greatest mandate".
"If the party with the greatest mandate from the British people, if they wanted to reach out to the Liberal Democrats, of course I would listen," he told BBC radio.
Clegg's party could lose half of its 57 seats in the 650-seat House of Commons, however.
Miliband meanwhile, whose Labour party is heavily dependent on funding from trade unions, is reportedly planning to reach out to union leaders within days of the election result to seek support for their options for taking power.
All sides are also fighting a psychological battle to define what would be a "legitimate" government.
Under Britain's election system, it is possible that the Conservatives win the most votes but Labour takes office because they have more support from other parties.
Meanwhile SNP leader Nicola Sturgeon, whose party looks set to sweep Scotland despite their defeat in September's independence referendum, insisted any government must not just reflect the views of voters in England.
"The battle for victory at the general election has morphed into a fight to define the consequences of defeat," wrote one commentator in The Times newspaper.
The BBC's poll of polls puts the Conservatives and Labour within one point of each other, at 34 per cent and 33 per cent respectively - a position that has barely moved throughout the past five weeks of the campaign.
With little set to change in the final 48 hours, and no clear winner likely, many voters are behaving tactically.
A new ICM poll for The Guardian newspaper suggests that Conservative supporters in Clegg's constituency in Sheffield, northern England, are planning to vote for him amid signs he could lose his seat to Labour.
Meanwhile Conservative-supporting tabloid The Sun, Britain's top-selling newspaper, urged voters considering supporting the anti-EU, anti-immigration UK Independence Party (UKIP) to vote Tory to avoid letting in Labour.
UKIP, led by Nigel Farage, is polling in third place at 14 per cent but is unlikely to win more than a couple of seats. It currently has two members of parliament.
The Green party, which has one MP, is polling fifth after the Lib Dems on about five per cent.
Conservative finance minister George Osborne warned meanwhile that an indecisive election result could be "deeply unstable" for Britain.
He told the Financial Times that Britain's reputation for economic competence and stability could be destroyed in minutes if Labour wins.
In a later television interview he added: "The way to resolve this is for the British public, in the next three days, to send a clear signal to the politicians about what kind of government they want."