Ed Miliband
Ed Miliband Reuters

Ed Miliband's ailing leadership has taken another hit as one of its chief union backers claimed that Labour was heading for "electoral disaster".

Len McCluskey, general secretary of Unite, used a column in the Guardian to criticise the party's decision to back the government's public cuts and austerity measures, saying that shadow chancellor Ed Balls now represented "discredited Blairism".

"It also challenges the whole course Ed Miliband has set for the party and, perhaps, his leadership itself," said McCluskey. "Unions in the public sector are bound to unite to oppose the real pay cuts for public-sector workers over the next year. When we do so, it seems we will now be fighting the Labour frontbench as well as the government."

His comments have thrown into relief the question of how the political parties, which all support the cuts, will be able to sell the deeply unpopular policy of austerity.

McCluskey asked: "Where does this leave the half a million people who joined the TUC's march for an alternative last year and the half of the country, at least, who are against the cuts? Disenfranchised."

He rejected the argument that pay restraint would help create jobs and criticised the Labour Party for its failure to consult trade unions before making the "shift" in policy. The first that union leaders knew of Balls's speech was when they were contacted by the media for their reactions.

A spokesman for Miliband rejected McCluskey's attack. "Len McCluskey is wrong about our policy now and our approach for the future," he said. "And Len McCluskey is wrong about what the last week showed for the Labour Party - a party united in its determination to pursue fairness even in tough times, make capitalism more responsible and protect our priorities."

RMT general secretary Bob Crow said: "Ed Balls and Ed Miliband doomed the Labour Party to electoral defeat by lining up with the Tory-led coalition's cuts and their attacks on public sector workers and that view is widely held across the trade union movement."