A surge in support for the Liberal Democrats has increased the prospect of a "hung parliament,” with no single party in control, for the first time since the days of the global oil crisis in 1974.
The opposition center-right Conservatives' once commanding lead in the polls has withered in recent weeks and they now lack the support needed to guarantee a return to power in the May 6 vote, after 13 years in opposition.
Five surveys to be published in Sunday newspapers put the Conservatives narrowly ahead of, or level with, the Lib Dems, with Prime Minister Gordon Brown's Labour Party third.
However, an Ipsos MORI poll for Sunday's News of the World bucked the trend, saying support for the Lib Dems appeared to be on the wane, putting the party well down in third place.
The election race has been thrown wide open by the recent rise in support for the centrist Lib Dems following the strong performances of the party's leader Nick Clegg in Britain's first US-style live televised debates.
Conservative leader David Cameron focused a campaign speech on Saturday almost totally on the risk he said a hung parliament would pose, particularly to the economy as Britain slowly emerges from the worst recession since World War Two.
Polls say the economy is far and away the voters' biggest concern and the issue has dominated the campaign.
"We need to win this argument in this election campaign that a hung parliament isn't a change for the better, it would be a change for the worse," said Cameron, adding it would leave politicians "bickering, horse-trading and arguing.”
Unlike western European parties, British parties have little experience of the negotiations that go with coalition building. Any power handover is almost brutally swift.
The familiar image the day after a sitting government is defeated is of the prime minister leaving his Downing Street residence, his goods dispatched in a removal van, and the new resident moving straight in.
RECORD DEFICIT
The prospect of an inconclusive election result has worried financial markets which fear a coalition government would fail to make spending cuts needed to tackle a record budget deficit.
However, analysts have suggested markets might be coming round to the idea that a hung parliament would not be as damaging as initially feared.
The Conservatives want to cut the deficit, running at more than 11 percent of GDP, more quickly and deeply than Prime Minister Gordon Brown's Labour government.
"Think about the threat of a hung parliament to our economy - a hung parliament where there's no agreement about getting on with dealing with the debt and deficit," Cameron told supporters in Thurrock, east of London.
Labour say Friday's lower-than-expected GDP figures support their stance that it is too early to make cuts.
"I will not hesitate to go round the country every day saying the Conservative Party are now the greatest risk to the economic recovery of this country," Brown said in a speech in Corby, central England.
With Labour trailing in the polls and the Lib Dems holding onto recent gains, media reports said Brown's party was rethinking its strategy. They said the prime minister was poised to become a more visible presence on the campaign trail, meeting with undecided voters rather than party supporters.
