Promising an in/out vote would shift the debate back onto Tory territory and allow Cameron to claim that Miliband is dancing to his tune.
The threat by Nissan to withdraw from Britain if the UK leaves the EU shows how the Tories' euroscepticism pulls against their emphasis on stability.
MPs who last year wanted the Labour leader to trump Cameron by calling for a snap poll on Europe say the moment has passed.
In defiance of ministers' claims, the new report finds that EU migrants are "less likely to receive disability and unemployment benefits".
UKIP leader denounces "this washed up politician" after he declares that Labour must "absolutely not" support a referendum on EU membership.
As Ed Miliband comes under pressure to promise a referendum, the former Labour leader warns that the dangers of an in/out vote are "massive".
Such a clear U-turn would cement a corrosive narrative that could prove far more damaging to his prospects of becoming Prime Minister – that of weakness.
The country's voters show little desire to proactively seek a resolution to the euro crisis.
The former election co-ordinator's call for an early EU referendum highlights the danger of Labour replicating Tory divisions over Europe.
A Conservative majority remains unlikely and EU treaty change could take many years to come to fruition.