Politics 19 December 2013 Why Labour's poll lead is small but very stubborn So long as Miliband retains the support of around 20% of 2010 Lib Dem voters, the Tories have no hope of victory. Sign up for our weekly email * Print HTML For the fourth Christmas in a row, Labour looks set to end the year ahead in the polls. With some exceptions, those commentators who dismissed Ed Miliband as "unelectable" in 2010 have now conceded they were wrong to do so. Labour is no longer achieving the double-digit poll leads it enjoyed last year but its lead remains stubborn enough for it to be confident of at least emerging as the single largest party in 2015. The central point in Labour's favour, as throughout this parliament, remains the large number of defectors from the Lib Dems. The party still reliably enjoys the support of nearly a quarter of 2010 Lib Dems voters, a swing greater than the cumulative increase in the Conservative vote between 1997 and 2010. It is largely for this reason that while Labour's lead has varied significantly in recent months (largely dependent on UKIP's level of support), its vote share has remained steady at 38-41% (within the margin of error), putting Miliband on course for victory. Aware that they are unlikely to poll above their 2010 share of 37% (GB figure), the Tories reportedly hope and believe that they can cap Labour's vote at 32%. But their fate remains largely out of their hands. Unlike previous parliaments, this one has seen remarkably little switching between the two main parties. As a result, there is little potential for the Tories to reduce Labour's support by winning over Conservative defectors. Instead, their chances of victory are dependent on a significant Lib Dem recovery. Unfortunately for Cameron, there is little prospect of this. As Lord Ashcroft's recent study of 2010 Lib Dem supporters noted, those who have defected to Labour are the least likely to return to the fold, with 78% saying they are certain how they will vote, compared to 69% of those who say they would Conservative, 62% of those who say they would vote UKIP and 42% of those who would vote Green. While existing Lib Dem MPs, many of whom enjoy large local followings, are likely to benefit from an incumbency effect, it is the Tories, not Labour, who will suffer as a result; Cameron's party is in second place in 38 of the Lib Dems' 57 seats. Elsewhere, support for Clegg's party is in freefall - and the Tories stand to lose dozens of seats; there are 37 Conservative-Labour marginals where the third place Lib Dem vote is more than twice the margin of victory. The Tories retain an unerring confidence that, confronted by the prospect of Miliband entering Downing Street, voters will recoil from Labour. By framing the election as a presidential contest – do you want Cameron or Miliband as your prime minister? – they believe they can overturn Labour’s lead (Cameron leads Miliband as people's preferred PM by 35-20 in today's YouGov poll). But this assumption is based more on faith than evidence. History shows that a well-liked (or, more accurately, less disliked) leader is no guarantee of electoral success. In the final poll before the 1979 election, Jim Callaghan enjoyed a 19-point lead over Margaret Thatcher as "the best prime minister" but the Tories still won a majority of 44 seats. Similarly, in the 1970 election, Harold Wilson's 23-point lead over Ted Heath failed to prevent Labour suffering a decisive defeat. Nor is economic recovery, however strong, likely to be enough to save the Tories. In large parts of the country, they simply remain too toxic for voters to lend them the support they need to beat Labour. As a recent YouGov poll found, 33% of the electorate would "never vote" Conservative, compared to 24% for Labour. Blue collar modernisers such as Robert Halfon and Guy Opperman understand what the Tories need to do to shed their reputation as the party of the rich. But cleansing the Conservative brand, as Cameron failed to do, will be the work of a decade, not 18 months. For the Tories, the really hard work is likely to begin after 7 May 2015. › Morning Call: pick of the papers David Cameron and Ed Miliband in Westminster Hall on June 21, 2012. Photograph: Getty Images. George Eaton is political editor of the New Statesman. Subscribe More Related articles I represent a Leave constituency - and I want to delay triggering Article 50 The SNP thinks it knows how to kill hard Brexit Supreme Court gives MPs a vote on Brexit – but who are the real winners?