Labour leads Tories by 10 points in new Guardian/ICM poll Some 41% of those polled said they would vote for Ed Miliband's Labour party. Photograph: Geoff Newton-Sportsphoto/Geoff Newton Replacing Nick Clegg with Vince Cable as leader of the Liberal Democrats would restore their poll ratings to heights not seen since the honeymoon period after they entered coalition in 2010 according to a Guardian ICM poll which also gives the Labour party its strongest lead over the Tories since Iain Duncan Smith was leader. If Vince Cable was leader at an election now the Lib Dems would gain five points, three from Labour, plus one each from the Tories and the assorted minor parties,the Guardian/ICM poll shows. It would take their rating from the current 14 to 19% - only five points down on 2010 election result. The poll also shows that the public is less than convinced by Clegg's YouTube apology last week for the party's broken pledge on student fees, Asked whether this rare show of political contrition made them "more likely to listen to what he has to say in future" only 20% of voters agreed, as against 69% who said they were now "less likely" to listen. The overwhelming 49 point gap between these two figures suggests the move backfired. Some 27% believe the government is shifting to the right, compared with 7% who say it is leaning more leftwards and 48% who believe it is staying centre ground. Labour has meanwhile assumed a commanding 10 point lead and would now take the votes of 41% of those polled, up two points on last month , while the Conservatives dropped back three to 31%, and the Lib Dems fell one, to 14%. Combined support for the assorted minor parties totals 14%. With the Liberal Dmeocrats assembled in Brighton for its annual conference, the new poll records a swing against the Lib Dems which would - with Clegg remaining at the helm - likely almost halve the size of the parliamentary party. Projections from the Electoral Calculus website imply that Clegg's caucus would shrink from 57 MPs today, to just 32 after a new election tomorrow. But if the reins passed to Cable - who on Monday distinguished himself from his leader by speaking to the conference about "social democratic values" - then some 50 Lib Dem parliamentarians are instead projected to survive. Some familiar Lib Dem names, such as the former children's minister Sarah Teather, are projected to be casualties in either scenario. But the seats of several others - including deputy leader Simon Hughes, Treasury chief secretary Danny Alexander and the former Scottish leader Malcolm Bruce, who recently made veiled criticism of Cable's seeming growing interest in a prospective future accommodation with Labour - might all be saved. A separate poll at the weekend, by YouGov for the Sunday Times, also suggested that replacing Clegg with Cable would increase the Lib Dems' rating by three or four points. After a mixed batch of recent polling for Labour, some of which has suggested that its leader is also sapping support, Ed Miliband will be delighted to see his party bursting through 40% threshold, for the third time this year in the Guardian/ICM series. He will be especially heartened that this comes at a time of Conservative weakness - the Tories' 31% showing is their worst in the series since September 2005, just before David Cameron became leader. It translates into doubling of last month's five point lead. Miliband briefly enjoyed an eight point edge in the Guardian/ICM series earlier this year, as did Gordon Brown at the time of the 2007 election that never was. Some other pollsters have methodologies that produce more volatile results and have occasionally recorded very large Labour leads recently, but in ICM's regular surveys for the Guardian, one needs to go back over nine years - to May 2003 - to find a more decisive Labour lead. At that point Tony Blair was still in Downing Street, and the recent victory over Saddam Hussein's Iraq had not yet been overshadowed by the descent into civil war. Just a few months before Duncan Smith went on to be ousted, the Tories lagged 12 points behind. One possible clue about the Conservatives' current difficulties comes from another question about the positioning of the government, after Cameron's reshuffle at the start of this month was widely reported as a move to the right. Although a plurality of voters, some 48%, still regard the coalition as "staying centre ground" a sizeable minority of 27% believe it is now "more right wing," as against only 7% who believe it has veered to the left. The breakdown of the vote for the minor parties is: Ukip 6%, Scottish Nationalists 4%, Plaid Cymru 1%, Greens 3%. The 6% showing for Ukip is higher than has been usual for ICM. ICM Research interviewed a random sample of 1,006 adults aged 18+ by telephone on 21-23 September 2012. Interviews were conducted across the country and the results have been weighted to the profile of all adults. ICM is a member of the British Polling Council and abides by its rules.