Lord McDonald, the former Foreign Office chief, claims Boris Johnson was briefed “in person” about the disgraced MP’s conduct in 2019.

Since the deputy chief whip resigned last week following allegations of groping two men, No. 10 has stated that the prime minister was not aware of any specific allegations.

However, Lord McDonald, the Foreign Office’s permanent secretary from 2015 to 2020, has written to parliament’s standards commissioner, claiming that Downing Street has made “inaccurate claims.”

“This morning I have written to the Parliamentary Commissioner for Standards – because No 10 keep changing their story and are still not telling the truth,” he tweeted.

He wrote in the letter: “The original No. 10 line is false, and the modification is no better. Mr. Johnson was personally briefed on the investigation’s initiation and conclusion.

“A ‘formal complaint’ was filed. The allegations were only resolved’ in the sense that the investigation was finished; Mr. Pincher was not exonerated. As a result, calling the allegations “unsubstantiated” is incorrect.”

Mr. Johnson presided over a cabinet meeting this morning, allowing cameras in for his opening remarks but not allowing journalists to ask questions.

The Prime Minister spoke about the cost of living crisis and his plans to address it, but there was no mention of Mr. Pincher or Lord McDonald’s letter.

Tory MP and PM critic John Penrose called the letter “dynamite,” tweeting that it demonstrated “another serious breach” of the ministerial code and that Mr. Johnson’s “promised reset” following Partygate had “no credibility because their behavior hasn’t changed at all.”

Shortly before the letter was published, Deputy Prime Minister Dominic Raab told that when he was Foreign Secretary in 2019, he was aware of the allegation.

He stated that he had “made it clear in no uncertain terms” to Mr. Pincher that the behavior “must never be repeated,” and that he had referred the matter to the civil service and the Cabinet Office for investigation.

However, Mr. Raab stated that the inquiries did not “trigger disciplinary action,” and that he had only recently informed the Prime Minister of the incident.

The deputy prime minister also called Mr. Pincher an “exceptional minister” and said it was appropriate to let the independent investigation reach its conclusions.

Labour’s deputy leader, Angela Rayner, stated that “it is now clear that the prime minister was aware of the seriousness of these complaints but decided to promote this man to a senior position in government anyway,” adding: “He refused to act and then lied about his knowledge.

“Boris Johnson is dragging British democracy into disarray. His heinous decision has made Westminster a less safe place to work.”

Mr. Pincher resigned as the government’s deputy chief whip on Thursday, following allegations that he drunkenly groped two men earlier that week at a private members club in London.

The party whip was only removed from him on Friday afternoon, leaving him as an independent MP for his Tamworth constituency, after the Prime Minister bowed to pressure and a formal complaint was made to parliament’s Independent Complaints and Grievance Scheme (ICGS).

Several ministers have since taken to the airwaves to reiterate Number 10’s defense of Mr. Johnson, including education minister Will Quince, who stated that the PM had given him “categorical assurance” that he was not aware of any serious specific allegations.

Emily Thornberry, Labour’s shadow attorney general, said Downing Street “tells us different things on different days… and as time goes on, the truth starts to come out.

She told that Mr. Johnson had been “turning a blind eye to any allegations because it was convenient for the prime minister to do so,” adding, “We need a country led by a decent, honorable person.”

Daisy Cooper, the Liberal Democrats’ deputy leader, said Lord McDonald had “shed a new light on this murky cover-up.”

She continued, saying: “Boris Johnson must admit to his web of lies and come clean today. Every day that this goes on, our politics is dragged deeper into the mud.

Brendan O’Hara of the Scottish National Party called for an investigation into the Prime Minister, saying the letter “demolishes Boris Johnson’s claims and raises serious questions about whether he has lied and broken the ministerial code”.