The Liberal Democrats would win almost twice as many seats at the next election under Vince Cable as they would under Nick Clegg, according to a ComRes survey for The Independent.
According to ComRes, the Liberal Democrats would win 18 per cent of the vote with Mr Cable as leader, compared to 14 per cent under Mr Clegg. Under the Business Secretary, they would hold 39 of their 57 seats on a uniform swing, while under the Deputy Prime Minister they would be left with only 23 MPs.
The dramatic findings will fuel the debate inside the Liberal Democrats over whether Mr Clegg is the right man to lead them into the 2015 election. The first poll to test that supports claims by Mr Cable's allies that installing him would boost the party's appeal. ComRes found that the Liberal Democrats would do much better among men with the Business Secretary as its leader. Their 12 per cent rating under the Deputy Prime Minister would rise to 18 per cent under Mr Cable, who would also boost their support among women from 15 to 18 per cent.
It appears Mr Cable, seen as more left-wing than Mr Clegg, would attract voters from across the political spectrum. Under Mr Clegg, only 53 per cent who say they voted Liberal Democrat in 2010 would support the party in an election now. That figure would rise to 62 per cent under Mr Cable.
Some 2 per cent of those who backed Labour in 2010 would support the Liberal Democrats under Mr Clegg, while 5 per cent would do so if Mr Cable were leader. Among Tory voters in 2010, the proportion voting Liberal Democrat would rise from 4 per cent under Mr Clegg to 6 per cent under the Business Secretary.
Labour's 11-point lead over the Conservatives in the last ComRes poll for The Independent in July has dropped to seven points. Labour is on 42 per cent (down two points), the Tories on 35 per cent (up two points), the Liberal Democrats on 12 per cent (up two points) and others on 11 per cent (down two points).
Ed Miliband appears to be a slight drag on the Labour Party. When he is named as the party leader in the poll question, Labour's rating falls from 42 per cent to 39 per cent. In contrast, Mr Clegg seems to be slightly more popular than his own party.
Aides insist Mr Clegg will not "bale out" before the election and dismissed the speculation about his position as "ludicrously premature".
Mr Clegg will meet the party's MPs and peers at his routine weekly meeting tonight. Lorely Burt, the MP who chairs the parliamentary party, urged Mr Cable to rein in supporters including Liberal Democrat peers Lord Oakeshott and Lord Smith. She said: "Who is Lord Smith? He is nobody and he should keep his trap shut."
ComRes interviewed 1,002 GB adults by telephone between 31 August and 2 September. Data was weighted to be demographically representative of all GB adults. Data was also weighted by past vote recall. ComRes is a member of the British Polling Council and abides by its rules.