The man who helped run Project Fear is now a key figure in Brexit negotiations

The political spinner who worked for George Osborne at the height of his bid to keep Britain in the EU, will now take a top job at the Whitehall department responsible for pulling the UK out of it.

The bizarre twist will see ex-Treasury Special Advisor James Chapman working as a top aide to the new Brexit Secretary David Davis.

It comes after ex-Daily Mail Political Editor Mr Chapman was left in limbo, when his old boss Mr Osborne fell from grace having failed to save the UK’s EU membership.

Mr Chapman spent six years in the Daily Mail’s most senior political position and was renowned for his calm approach, despite having one of the most demanding jobs on Fleet Street.

But last May he was tempted away from journalism to take up a post with Mr Osborne, who at the time looked like the strongest Tory contender to succeed David Cameron as Prime Minister.

The job saw Mr Chapman helping the ex-Chancellor pull together his communication strategy for the EU referendum campaign, something later branded “project fear” by critics in the Leave camp.

Ironically, one of the biggest critics of them all was Mr Davis, for whom Mr Chapman is now expected to be Chief of Staff.

On one occasion during the campaign after Mr Osborne’s warnings of economic doom and Mr Cameron’s claims that Brexit risked future conflicts, Mr Davis said: "Earlier in the week when we had the warnings about an imminent World War III, I thought ‘what next, a plague of locusts?’"

"It's not biting. The Obama thing didn't bite, the Treasury thing bit for two days and then it died.”

A Whitehall source told The Independent today that the move was “not so much poacher turned gamekeeper, as gamekeeper turned poacher.”

Mr Chapman’s wife, who is Greek and an EU citizen, may also take a view on her husband’s new post.

The former hack will have known and worked closely with Theresa May’s new senior communications advisors Fiona Hill and Katie Perrior during his time at the Daily Mail.

One Westminster insider said the appointment indicated that Downing Street intended to work “in lockstep” with Mr Davis.

But in his new role Mr Chapman will have his work cut out, managing a strong-minded minister responsible for one of the highest profile Whitehall fiefdoms.

The Department for Exiting the EU is also at the centre of a turf war with Boris Johnson’s Foreign Office and Liam Fox’s Department for International Trade.

Mr Chapman did not respond to requests for a comment.