Boris Johnson today waded into the debate over the European Union with a call to David Cameron to reject “nonsensical” plans for closer integration to bolster the eurozone.
The London mayor made clear that he regarded Government support for greater fiscal union among the 17 eurozone states as "misguided" and "wrong".
His intervention - following reports that eight members of the Cabinet including Education Secretary Michael Gove believe Mr Cameron should threaten to quit the EU unless Britain is offered a new, less binding relationship with Brussels - will pile further pressure on the Prime Minister.
A source close to Mr Johnson told the London Evening Standard: "He welcomes any heavyweight support for the idea that Britain needs to fundamentally re-frame its role in Europe.
"The idea of closer economic and political integration is nonsensical. We need to resist all moves to further erode democracy in Europe and closer integration means just that, with Germany's position strengthened and everyone else's hopelessly weakened.
"Government support for greater fiscal union wouldn't just be misguided, it would be wrong."
Downing Street however insisted it was necessary for the eurozone states to integrate more closely if the problems of the single currency bloc were to be resolved.
"Clearly we want them to resolve the eurozone crisis as soon as possible. Further integration is an inevitable part of that process," a No 10 spokeswoman said.