One quarter of voters uncertain as Labour sag at the final post

More than a quarter of the electorate is still undecided about how to vote today, an NOP poll for The Independent found.

More than a quarter of the electorate is still undecided about how to vote today, an NOP poll for The Independent found.

The survey suggests Labour is on course for a third successive term but that a last-minute advance by the Liberal Democrats leaves Tony Blair uncertain that he will secure a big enough majority to serve the "full term" he wants before standing down.

Labour's 10-point lead in NOP's poll last week has slumped to three points after the closing stages of the campaign were dominated by Iraq.

The party, on 36 per cent, is down four points, while the Tories (33 per cent) are up three. The Liberal Democrats are up two points to 23 per cent, their highest rating since NOP began its pre-election series for this newspaper last October.

If this proves to be the result tonight then Labour will secure a lower share of the popular vote than any previous majority government. Although the figures point to a Labour majority of more than 90, Blair aides are worried that the winning margin will be smaller because of wide variations in different seats and a tight race in the marginals.

They are particularly nervous about the rise of Charles Kennedy's Liberal Democrats, fearing it could allow the Tories to win between 20 and 30 Labour-Tory marginals where they are in third place by taking votes away from Labour.

Another sign that the election is still open is the unusually high number of people - 27 per cent - who might change their mind about how to vote even at this late stage. They include 36 per cent of those intending to support the Liberal Democrats.

Both Labour and Liberal Democrat supporters are more likely to switch to each other than move to the Tories, while Tory supporters, by a margin of almost three to one, are more likely to transfer to Mr Kennedy's party than Mr Blair's. The doubts among Labour supporters are shown by NOP's finding that only 76 per cent of Labour voters would be happy tomorrow if the party wins the election, compared to 85 per cent of Conservative voters.

However, Labour will be buoyed by signs of a higher turnout than the 59 per cent seen at the 2001 election, with 70 per cent of people now saying they are certain to vote - up eight points since last week.

Labour supporters (78 per cent) remain less likely to say they will turn out to vote than Tories (84 per cent) but more likely than Liberal Democrat supporters (72 per cent). The number of Labour supporters saying they are certain to vote has risen from 67 per cent to 78 per cent since the start of the campaign, which will reassure Labour strategists.

A Labour victory would not be widely welcomed. Only 33 per cent of people say they will be happy if Labour wins - only slightly above the proportion who would be happy to see the Conservatives win (27 per cent) - while 30 per cent will be unhappy.

After the leaders of the three parties criss-crossed the country in a blitz in the marginal seats, they made their final pitch in BBC television interviews last night.

Mr Blair denied he had been campaigning simply to keep the Conservatives out of power but predicted a "tight" and "tough" contest. "There's a massive amount positive to vote for. In the end it's a choice - a Conservative government or a Labour government and we believe a Conservative government is a risk," he said.

Michael Howard, the Tory leader, defended his decision to brand Mr Blair "a liar" over the war in Iraq and urged people to vote for a "brighter, better tomorrow". He said: "Character is an issue with this election and trust is an issue. If you look at the promises that were made and broken, people have to ask themselves how they can believe the promises made to them by Mr Blair in this election."

Mr Kennedy said: "I think the story of this campaign for millions of people has been the steady rise of the Liberal Democrats. All the evidence is that's accelerating in the closing days while the Conservatives have gone down." He dismissed Labour's claims that a vote for the Liberal Democrats might result in a Tory government. "It's just not going to happen and they are rattled," he said.

Other polls published today show Labour going into the election with a lead of between five and six points. ICM in The Guardian puts Labour on 38 per cent, the Tories on 32 per cent and the Liberal Democrats on 22 per cent, while Populus for The Times shows Labour on 38 per cent, the Tories on 32 per cent and the Liberal Democrats on 21 per cent.

A YouGov survey for The Daily Telegraph puts Labour on 37 per cent, the Conservatives on 32 per cent and the Liberal Democrats on 24 per cent.