THE chief of Downing Street’s beleaguered Union Unit has quit after just two weeks in the job. 

Oliver “Sonic” Lewis unexpectedly left the post on Friday, with reports saying he felt his position was being made “untenable” by others in No 10. 

He’s supposedly the latest casualty in a Whitehall turf war involving the Prime Minister’s fiancee Carrie Symonds. 

Last Friday Johnson appointed Simone Finn as his deputy chief of staff and former Michael Gove aide Henry Newman as his new senior adviser. 

Newman has previously worked with Gove on Union strategy, and, according to reports, the more combative Lewis - a protege of Dominic Cummings - was worried the appointment would mean less free rein for him. 

Lord David Frost, the UK’s Chief Brexit negotiator was also set to quit over the appointments, fearing it meant a change in approach to Brexit.

Johnson kept him on board by promoting him to the Cabinet. 

He was given more responsibilities, taking Gove’s job as UK chairman of the withdrawal agreement joint committee, and leading on talks on easing trade restrictions between Great Britain and Northern Ireland.

A number of papers quoted sources saying that Frost’s promotion was a “sidelining” of Gove, and a sign of his waning influence. 

According to the Times, Lewis quit after Johnson effectively accused him of being the source. 

SNP leader Nicola Sturgeon took to Twitter to suggest Lewis had left after "realising how threadbare the case" was for the Union.

Plaid Cymru leader Adam Price tweeted: "The Prime Minister can't unite an unit let alone 'the kingdom'."

The unit was established after the 2019 General Election saw a resurgent SNP take 48 of Scotland's 59 seats. The Scottish Tories saw their numbers fall from 13 MPs to just six. 

One of those who lost their seat was Luke Graham. He was appointed to the unit and given the brief of making the UK more attractive to Scots.

But with poll after poll putting independence ahead, Tory high command moved to reshape the unit, making it a directorate, and appointing "street fighter" Lewis.

Reports at the time said Graham had been binned to make way for Lewis.

“Oliver Lewis needed a new job and he wanted Luke’s. He’s an old pal of Boris’s from Brexit days so he got the job,” a source close to Graham told The Times.

SNP Westminster Deputy Leader Kirsten Oswald MP said:"Boris Johnson's taxpayer-funded anti-independence campaign is completely falling apart - as Oliver Lewis becomes the second Head of the Tory Union Unit to quit in a fortnight.

"As support for independence grows, the Tories are losing advisers like rats on a sinking ship. People in Scotland have a right to determine their own future in a post-pandemic referendum. Boris Johnson knows he cannot deny democracy any more than Donald Trump."

During his time in charge, Lewis started recruiting for people to join him in the Union Unit.

Though the adverts for the posts were mocked by the SNP for saying "understanding of policy issues relevant to Scotland, Wales and Northern Ireland" were only "desirable" and not "essential" skill.

The advert also said recruits would "need to be resilient under pressure and flexible in response to changing circumstances and tight timetables".