Britain’s defence secretary Gavin Williamson was sacked this evening in extraordinary style, over accusations that he was responsible for the National Security Council leak concerning Chinese telecoms giant Huawei last week.

A statement from a Number 10 spokesperson said the Prime Minister has “lost confidence in his ability to serve in the role of Defence Secretary and as a member of her cabinet.”

It added: “The Prime Minister’s decision has been informed by his conduct surrounding an investigation into the circumstances of the unauthorised disclosure of information from a National Security Council.”

But Gavin Williamson has repeatedly, and vociferously, denied he is the source of the leak. In a letter published around 7pm Williamson wrote: “I am sorry that you feel recent leaks from the National SecurityCouncil originated in my Department. I emphatically believe this was not the case… I am confident that a thorough and formal inquiry would have vindicated my position.”

Williamson told Sky News he isn’t the source of the leak, and the Prime Minister has no evidence to the contrary. And that he believes this sacking to be the “settling of a vendetta” between him and the cabinet secretary, top civil servant, Mark Sedwill, who led the investigation.

Williamson told The Sun he would insist to his “dying day” that he did not leak this information.

This is a remarkable end to the cabinet career of a politician who enjoyed a swift rise through the ranks of the party. He served as a Conservative councillor in North Yorkshire from 2001-2005, during which time he was also a fireplace salesman. He took his seat as MP for South Staffordshire in 2010.

In 2011 he was appointed Parliamentary Private Secretary to Minister of State for Northern Ireland, Hugo Swire. By 2013 Williamson was PPS to Prime Minister David Cameron. The former Tory leader trusted Williamson, who got used to the idea that he had been tipped for the very top.

Williamson campaigned to remain in the EU, and following Cameron’s resignation backed May to be the next leader. He was her parliamentary campaign manager, and following her accession to Prime Minister, Williamson was appointed Chief Whip.

In 2017 Williamson was appointed Defence Secretary, following Michael Fallon’s resignation. A far cry from his first notable move in parliament: calling for a new law to clamp down on car boot sales that disrupted traffic flow.

But despite a remarkable career trajectory, Williamson hasn’t always held favour with many of his colleagues.

Chief whips tend to make enemies, it is in the nature of the job. But Williamson – having risen so rapidly and being unafraid to brief out in his own favour – was especially unpopular. The suggestion was that he helped engineer the departure of Sir Michael Fallon, the previous defence secretary, only to land up with the job himself. How convenient.

Says a minister who clashed repeatedly with Williamson: “He was out of his depth and untrustworthy. I’m glad this has happened.”

Another said: “Gavin is gauche. He had it coming.”

Williamson garnered a particularly Baldric-esque reputation for himself – forever coming up with dud cunning plans. In the wake of the Salisbury poisoning, he told journalists that “frankly, Russia should go away, and it should shut up.” Spokesman for the Russian Defence Ministry, Igor Konashenkov, responded to this particular gaff with damning commentary: “The market wench talk that British defence secretary Gavin Williamson resorted to reflects his extreme intellectual impotency.”

In his first few weeks on the job as Defence Secretary, the book White Flag recounts, Williamson visited Sandhurst where the officer cadets were “so immaculately turned out they could see their own reflections in their buttons.” Williamson showed up with what appeared to be shaving foam on his chin.

Penny Morduant will take over as Secretary of State for Defence, as the first woman to take that position. Rory Stewart will take up her role as International Development Secretary.

Williamson insists he is not responsible for the leak. He refused the offer of resignation from Theresa May – so she was compelled to fire him: “I’m grown up enough to understand this is politics” he said. He then swore his innocence “on his children’s lives.”

Outraged friends (he has some) of Williamson are tonight demanding that May produces the evidence. There are more chapters to come in this Whitehall thriller.