The leader of Britain's biggest trade union has warned Ed Miliband that unless Labour offers "real alternatives" to David Cameron's austerity programme he will lose the election - and risk losing the financial support of the union.
Speaking to journalists at a lunch in Westminster on Tuesday afternoon, the general secretary of the Unite union, Len McCluskey, said a Labour programme that simply offered "variations of austerity" was not good enough. And he warned that many Labour MPs were worried there was no "cohesive vision" coming from the party leadership.
Unite is the biggest donor to the Labour Party. It gave £11m to the party since Miliband became leader. And under current rules it is only allowed to donate to Labour. But McCluskey said if the party failed to offer a real alternative to the coalition's economic austerity measures then he could imagine moves being made within Unite to disaffiliate from the party. This would allow the union to channel its substantial funds to other parties.
"That's a challenge to Ed Miliband," McCluskey said. "I believe the Labour Party is at a crossroads. This is a watershed. Labour consistently has to demonstrate that it is our voice, we created it. Ordinary people sat down to create a party of labour so we had a voice."
"Is Labour still that voice? I'm hoping the answer to that is yes. We are at a stage in politics at the moment where just bumbling along int the old ways is not going to happen anymore."
"Unless Ed and Labour leadership demonstrate they are on our side ... then I can envision a debate taking place. If labour lost the election next May I fear for the future of the Labour Party."
In recent weeks Labour's poll lead over the Conservatives has narrowed - leading to internal debates over the party's election strategy to spill out into the open. McCluskey said the "rumbling and grumblings" of Labour MPs was because "people are getting slightly uneasy there isn't a cohesive vision emerging".
McCluskey said the party had to offer voters a real alternative in 2015 of it would be defeated. "If it's a pale shade of austerity then I believe Labour will be defeated at the next election," he said.
"Internally in the Labour Party there is an argument going on between those who want a transformative programme, as they call it, and those who want to shrink the offer. If we do that we will lose. If we put forward hope then I believe that Labour will come back into power," he said.
"Miliband has got to give hope to people. He has got to demonstrate he will do something different in power. If he does that with a passion, if he does that with some conviction. Then in my view the polls will begin to alter. He will begin to be seen as a genuine alternative."
In recent days there have been reports of an internal battle at the top of the party including between election co-ordinator Douglas Alexander and vice chairman of the party Michael Dugher. Asked what he thought of Alexander's election strategy, McCluskey replied simply: "He's our leader".
In an interview with The Huffington Post UK, Jon Trickett, shadow minister without portfolio and the deputy chair of the party, said Labour needed to use "plan language" to communicate with voters. He said Labour needed to "make the case for big change, radical transformation and a reconnection with those people who left Labour."