Tony Blair is the only senior Labour figure who would transform Labour's prospects at the next general election, according to a ComRes poll for The Independent.
The former prime minister would cut the Conservative Party's projected majority of 182 to just 20 seats – enough to raise Labour's hopes it could prevent David Cameron becoming Prime Minister. The Tories' current poll lead would be almost halved from 19 to 10 points.
The good news for Gordon Brown is that none of the alternative leaders being touted as his possible successor would secure Labour more public support than he is winning.
Under David Miliband or Jack Straw, Labour's ratings would be exactly the same as under Mr Brown, while the party would perform worse if Alan Johnson, Harriet Harman or Ed Balls took over.
Although the survey shows Mr Brown is unpopular among Labour supporters, it suggests the Labour brand is now tarnished in the eyes of many voters – another sign that changing its leader might have little impact.
Some 49 per cent of the public say they do not like Mr Brown or the Labour Party. Only 16 per cent say they like him and the party. Mr Brown is slightly less popular than his party: 20 per cent of people say they like Labour but not him, while 8 per cent like him but not the party.
Remarkably, 34 per cent of people who intend to vote Labour say they like the party but not Mr Brown. Only 3 per cent of them like him and not Labour, and just 58 per cent of Labour supporters like both the party and its current leader.
Among people who are undecided or who refuse to say how they will vote, 44 per cent say they do not like Mr Brown or Labour. Only 12 per cent like the party but not the Prime Minister, suggesting Labour's problems go much deeper than its leader.
The survey puts the Tories on 44 per cent (down two points on the last monthly ComRes poll), Labour on 25 per cent (up one point), the Liberal Democrats on 17 per (down one point) and other parties on 14 per cent (up two points). Those figures would give Mr Cameron an overall majority of 182 if repeated at a general election.
Labour's rating would remain at 25 per cent if Mr Miliband, the Foreign Secretary, or Mr Straw, the Justice Secretary, were leader, the poll finds. Under Mr Johnson, the Health Secretary, and Ms Harman, Labour's deputy leader, the party's rating would slip to 23 per cent, while under Mr Balls, the Schools Secretary, it would fall to 22 per cent.
Under Mr Blair, Labour would win 31 per cent, reducing the projected Tory majority to just 20 seats. Mr Blair, who is more popular now than when he left Downing Street last summer, cannot return as leader because he is no longer an MP, but according to ComRes, he would enjoy much more support among both men and women than any other Labour figure including Ms Harman. Mr Blair would win the backing of 31 per cent of women and Ms Harman 23 per cent.
Labour MPs who want the Cabinet to oust Mr Brown had been hoping that polls would show that a change of leader would close the gap with the Tories – in the hope of creating a bandwagon effect for Mr Miliband, the front-runner to succeed him.
While Mr Brown's allies will be relieved by the findings, his critics will argue that they reflect the fact that politicians such as Mr Miliband and Mr Johnson are not as well known by the public as Mr Brown or Mr Blair—and that a new leader would soon enjoy a much higher profile.
The finding that Mr Blair would close the gap will give Labour a ray of hope that the Tories' lead is "soft", showing hostility to the Government during the economic downturn rather than positive support for Mr Cameron's party. Privately, some Tory strategists believe their party's "real" lead is more like 10 than 20 points.
Labour critics of Mr Brown still insist that a change of leader could spark a revival for the party. They point out Mr Brown received a bounce in the polls after succeeding an unpopular Mr Blair 16 months ago, only to squander it by calling off plans for an autumn election.
For the poll, ComRes interviewed 1,013 British adults on 3-4 September. Data was weighted by past vote recall. ComRes is a member of the British Polling Council and abides by its rules. Full tables can be viewed at www.comres.co.uk