The drop in support for the Liberal Democrats is boosting Labour as well as the Tories, according to a new study for The Independent.
A "poll of polls" by John Curtice, professor of politics at Strathclyde University, shows that Labour is narrowly ahead of the Tories, and on course to retain power at the next election despite the Tory recovery under David Cameron.
Until now, it has been assumed that the turmoil in the Liberal Democrats since the resignation of Charles Kennedy would mainly benefit the Tories. The Cabinet was told this month that two out of three voters deserting the Liberal Democrats are switching to the Tories, and Labour fears a third party collapse could severely harm its prospects at the next election.
The weighted average of this month's polls by ICM, MORI, ICM and Populus puts Labour on 39 per cent (up four points on last month), the Tories on 38 per cent (up one point) and the Liberal Democrats on 16 per cent (down four points).
That would give Labour 354 MPs and the Tories 235. The number of Liberal Democrat MPs would more than halve from 62 to 29. Labour would enjoy an overall majority of 52 - although proposed changes to constituency boundaries could reduce that.
Professor Curtice said the fall in Liberal Democrat support could help Tony Blair to survive the local elections in May without demands from his own party that he should stand down, rather than allow Mr Cameron to demonstrate his electoral power.
He said: "The Lib Dems have managed to do far more damage to themselves than David Cameron was ever able to inflict on them. The principal beneficiaries of the Lib Dem fall since Christmas are Labour, not the Conservatives. This has enabled Labour to restore its share to what it was before Cameron was leader."
"The story of December was that the election of Cameron hurt Blair, while the lesson of January is that the fall of Kennedy has helped Blair."
Professor Curtice said the conventional wisdom at Westminster that Mr Cameron was hurting the Liberal Democrats, and that their problems were good news for the Tories "does not fit the facts". Labour now profits from a decline in the third party's vote, as well as the Tories, because the Liberal Democrats made advances in Labour territory at last year's general election, he said. The latest "poll of polls" would allow the Tories to capture 20 Liberal Democrat-held seats but Labour would win another 12 of them.
Professor Curtice said it was no surprise that Labour appeared to be the main beneficiary of the Liberal Democrats' decline. Data from the 2005 British Election Study shows that for every vote the Liberal Democrats gained from the Tories last year, they gained three from Labour.
"So, if those last in are most likely to be first out, and deserters are most likely to return to their party of origin, then we should expect a decline in the Lib Dem vote to be of more benefit to Labour than the Conservatives," he said.
An ICM poll in TheSunday Telegraph showed that 39 per cent of Liberal Democrat supporters believed the party would be better off with Mr Kennedy as leader. But 47 per cent thought it would be better to have a new leader.
The survey, which gave the Tories a one-point lead over Labour, found that the recent scandals in the Liberal Democrats had made 16 per cent of voters less likely to back the party, 2 per cent more likely while 80 per cent said they had made no difference.
There was good news for the Liberal Democrats when Sir Cyril Townsend, a former Tory MP, announced he had defected to them. He is supporting Sir Menzies Campbell's bid to succeed Mr Kennedy.
Sir Cyril, the MP for Bexleyheath from 1974 to 1997, said: "David Cameron was the author of Michael Howard's illiberal manifesto just last May. If he believed what he wrote then, how can he believe what he says now?Reuse content