Labour shadow home secretary Andy Burnham has predicted Britain will vote to leave the European Union.
The former leadership candidate reportedly told the Cambridge Universities Labour Club that in the country the "mood is not to stay in".
"If I was to lay money on it now, tonight, I would bet that Brexit is going to win, and I don’t like saying that, but I feel that from talking to people in my own constituency," he said.
In comments reported by Varsity, the Cambridge University student newspaper, Burnham said the benefits of the EU outweighed the downsides despite Brussels having been "remote", "arrogant", and "anti-democratic" at times.
On Monday, Boris Johnson said President Obama's intervention in the EU referendum debate was a "piece of outrageous and exorbitant hypocrisy".
The US president's warnings that Britain will lose influence on the world stage if it quits the 28-member bloc are also "wholly fallacious", according to the London Mayor.
In his regular Daily Telegraph column, Boris wrote: "Sometime in the next couple of months we are told that president Obama himself is going to arrive in this country, like some deus ex machina, to pronounce on the matter.
"There is no country in the world that defends its own sovereignty with such hysterical vigilance as the United States of America. This is a nation born from its glorious refusal to accept overseas control."
Obama is expected to visit the UK next month and urge the British public to vote to stay within the EU.
The president has on many previous occasions said he wants the UK to remain a member.
Downing Street has defended the right of Obama to intervene, with David Cameron's official spokeswoman insisting the president's views are "worth listening to".