The boss of Britain's biggest trade union has warned that it could switch its financial support from Labour to another party.
Unite general secretary Len McCluskey said defeat in 2015 could prompt the union to consider disaffiliating from Labour.
The union has donated more than £11 million to Labour since Ed Miliband became leader. But Mr McCluskey said that he "fears for the future" of the Labour Party if it fails to regain power in next year's general election.
He said: "Can I ever envisage a rule conference voting to disaffiliate from Labour? I can do."
The union boss predicted Labour will lose the May 2015 poll if all it has to promise voters is a "pale shade of (the) austerity" on offer from Conservatives.