Labour has vowed to carry on fighting to polling day after Gordon Brown failed to make the party's hoped-for breakthrough in the final leaders' debate.
A clutch of instant polls following the last of three televised head-to-heads made David Cameron clear winner, with the Prime Minister again trailing in third place.
With just a week to go and Labour still behind in the overall opinion polls, the party had been hoping desperately that Mr Brown would put in a performance that would change the dynamics of the campaign.
Mr Cameron cautioned that the election was "far from won" for the Conservatives and said that he would spend the next six days concentrating on winning every vote.
Labour election co-ordinator Douglas Alexander also insisted that the result of the election remained "wide open", and said that Mr Brown would carry on fighting until the end.
"He is going to be campaigning the length and breadth of the country in the days ahead," he told Sky News. "We are going to be fighting from now until the election for every single vote. This election is wide open. Nobody has any certainty how this election will play itself out."
But Liberal Democrat foreign affairs spokesman Ed Davey said Labour was out of it and the contest now was between his party and the Conservatives. "This is turning into a two-horse race. Unexpectedly, it is between the Liberal Democrats and the Conservatives," he said
Mr Cameron said it was essential that the Tories did not let up in the final run-in to polling day. "I am just very focused on the next week because this is still an election where we have to fight for every vote and every seat," he told BBC Radio WM.
"I am going to be doing everything I can in these next six days to say to people if you want real change, if you want to wake up on Friday May 7 with a different government, with a new prime minister, taking the country in a new direction, then please vote Conservative because this election is still far from won."
In his closing statement before a studio audience at the University of Birmingham, Mr Brown made his clearest admission yet that Labour could be facing the prospect of defeat on May 6. "I know that if things stay as they are, perhaps in eight days' time David Cameron, perhaps supported by Nick Clegg, would be in office," he said.