Conservative MP Oliver Letwin has apparently had a road to Damascus-style conversion and said that Britain should leave the EU if David Cameron cannot renegotiate Britain’s position.

According to the Huffington Post, the author of the 2010 Tory general election manifesto, who sits so far on the left of the party that he has been dubbed “Oliver Leftwing”, told students at University College London he was not “100 percent sure” that David Cameron could secure reform of the EU.

In the week that the Conservatives are set to lose a second by-election to UKIP – this time in a seat which fits the profile of a safe Tory seat – Mr Letwin said he wanted Britain to avoid being absorbed into “a United States of Europe”.

“If we can achieve that in negotiations then I shall certainly be supporting remaining within it in the referendum in 2017,” said the Cabinet Secretary.

“We have to have that referendum. We have to put to the British people that question. We will see whether what we are able to negotiate is acceptable. I think they deserve that choice.”

“If we don’t get the sort of position that I was describing then I wouldn’t want to recommend staying, I would want to recommend leaving. It’s better than being absorbed into a United States of Europe.”

The 2010 Conservative Party manifesto was supportive of Britain’s membership of the EU and during the coalition government’s time in office the Tories have signed the country up to measures which hand over power to Brussels.

It said:

“The European Union has done much to reconcile the painful division of Europe and to spread democracy and the rule of law across our continent. But it should not rest on those achievements.

“European countries need to work together to boost global economic growth, fight global poverty, and combat global climate change. The European Union has a crucial part to play in enabling the countries of Europe to meet these great challenges of the 21st century. A Conservative government will play an active and energetic role in the European Union to advance these causes.”

When in opposition, Mr Letwin was notable by his absence on a large number of votes particularly when the Lisbon Treaty was being debated in Parliament including when MPs were voting on whether the President of the EU should have control over foreign policy.

Since 2010 the man who has been a key ally of Mr Cameron and pushed through his reform agenda has voted for the EU External Action Service, British tax payers bailing out eurozone countries as well as a continued close working relationship between the UK and other EU states on criminal justice and data protection.