The shadow Chancellor, Ed Balls, said yesterday that Labour could not dismiss the possibility of calling a referendum to see whether the public wanted to pull out of the EU altogether.
"I don't think you should ever say that the public shouldn't be consulted as part of the discussion and in some ways part of Europe's problems is that it has been seen to be run too much by elites," he told Sky's Dermot Murnaghan.
But he added: "I don't think that's a priority. A jobs and growth plan I think is more in tune with what the public wants than going into an internal and navel-gazing debate now about Europe," he said. This month, Ed Miliband gave the Labour MP and former Downing Street adviser Jon Cruddas responsibility for Labour's policy review.
Mr Cruddas is one of a growing number of politicians who support continued membership of the EU but agree with its opponents that there should be a referendum to clear the air.
The pressure group People's Pledge, a coalition of supporters and opponents of EU membership who agree on the need for a referendum, has picked up support from 68 MPs.