Elections 21 July 2010 Unison endorses Ed Miliband for Labour leader Miliband has now won two of the “big three” trade unions. Sign up for our weekly email * Print HTML David Miliband may be steaming ahead in the polls, but it's Brother Ed who's winning over the trade unions. A few minutes ago, the 1.3 million-strong Unison announced that it would be supporting him in the Labour leadership election. Miliband has now won the backing of two of the "big three" unions (the GMB nominated him last week), with only Unite left to declare. Ed Balls's team has long been hopeful of winning the Unite nomination, but Miliband has some significant backers in the union, including the joint general secretary, Derek Simpson, who anointed him as Labour's next leader in an interview with the NS in March. Since the abolition of the trade union block vote under John Smith, members have been free to vote as they wish, but in practice a significant number of Unison's members will back Miliband. In the 2007 deputy Labour leadership election, about 40-50 per cent of trade unionists voted for the candidate recommended by their union's leadership. The unions have given Miliband's candidacy the momentum it needs: Ladbrokes immediately shortened the odds on him becoming Labour leader. The challenge he now faces is to prove that he has popular appeal beyond his centre-left base. › David Miliband “greatest threat” to the coalition -- business leaders George Eaton is political editor of the New Statesman. Subscribe from just £1 per issue More Related articles Expressions of sympathy for terror's victims may seem banal, but it's better than the alternative Jeremy Corbyn fares well in his toughest interview yet Is the general election 2017 the end of Ukip?