Ed Miliband should rule out a coalition with the Liberal Democrats even if Labour fail to secure a majority in next year's general election, one of the party's biggest backers has said.
Unite General Secretary Len McCluskey urged Mr Miliband to say he would govern alone even if the party falls short of a majority in next year's general election.
The comments come amid reports that David Cameron will make a commitment not to sign another deal in the event of a hung parliament.
Speculation that a potential alliance between Labour and the Lib Dems has increased in recent months, after Nick Clegg praised the way the opposition had "changed" under Mr Miliband's leadership.
More top news
The comments came on the eve of an EU leaders' summit in Brussels, as Theresa May remains under pressure from the EU and her own Cabinet.
Cloudy skies with limited sunshine
Russell Bishop was cleared of killing nine-year-olds Nicola Fellows and Karen Hadaway following a trial in 1987.