The Staggers 14 May 2013 What if Labour wins on 34% or less of the vote? Some in the party fear it could face a "crisis of legitimacy" if it wins an outsized majority on a thin slice of the vote. Sign UpGet the New Statesman's Morning Call email. Sign-up The latest Guardian/ICM poll is as striking for Labour's low of 34 per cent as it is for UKIP's high of 18 per cent. But here's something else that's striking. If repeated at a general election on a uniform swing, that figure would give Ed Miliband a majority of 66 seats. What matters for the outcome of the next election is not Labour's vote share but its lead over the Conservatives (who are on 28 per cent). Assuming a Lib Dem share of 15 per cent, Labour needs a lead of just one per cent over the Tories to win a majority, so a lead of six points is more than enough. This apparent bias has less to do with the unreformed constituency boundaries than it does with the fact that Labour's vote is far better distributed than the Tories' and that it benefits disproportionately from tactical voting. So, what if Labour enters government on just 34 per cent (or less) of the vote? On one level, there should be no issue. The Conservatives can have no complaints about the outcome delivered by an electoral system they have consistently defended and Labour governed for a full term after winning on just 35 per cent of the vote in 2005 (it bagged 55 per cent of the seats). But party figures have told me that they fear Labour could face a "crisis of legitimacy" if it wins an outsized majority on a thin slice of the vote. A share of 34 per cent would be the lowest winning percentage of the vote since 1832. Labour may have won on only 35% in 2005 but that victory was at least preceded by two others. For a newly-elected government, likely to preside over further austerity, a weak mandate would be a far greater hindrance. With that in mind, now might not be a bad time to restart that dormant electoral reform debate. › Does the New York Times actually want anyone to read Angelina Jolie's piece? Ed Miliband speaks at last year's Labour conference in Manchester. Photograph: Getty Images. George Eaton is senior online editor of the New Statesman. Subscribe For daily analysis & more political coverage from Westminster and beyond subscribe for just £1 per month!