Cabinet Secretary Simon Case last night "recused himself” from leading the investigation into lockdown-breaking parties alleged to be held across Whitehall last year as the pandemic's second wave was hitting the UK.
The decision comes just eight days after Boris Johnson had tasked Mr Case with the probe into parties reported to have been held in Downing Street and the Department for Education in November and December 2020.
Downing Street confirmed the probe would now instead be concluded by senior civil servant Sue Gray.
A No. 10 spokesperson said: “To ensure the ongoing investigation retains public confidence, the Cabinet Secretary has recused himself for the remainder of the process.
“The work will be concluded by Sue Gray, second permanent secretary at the Department for Levelling Up, Housing and Communities.
“She will ascertain the facts and present her findings to the Prime Minister.”
The statement was issued after details emerged yesterday afternoon that a virtual quiz had been held on December 17 last year for members of Mr Case's private office.
Invites were allegedly sent out titled "Christmas Party!". The event is believed to have involved six people in the office and around another six taking part at home.
The day before the event, on December 16 last year, London had entered tier three Covid restrictions, forcing pubs and restaurants to close and banning different households from mixing indoors.
A Cabinet Office spokesperson said last night: “Staff in the Cabinet Secretary’s private office took part in a virtual quiz on December 17, 2020.
“A small number of them, who had been working in the office throughout the pandemic and on duty that day, took part from their desks, while the rest of the team were virtual.
“The Cabinet Secretary played no part in the event, but walked through the team’s office on the way to his own office.
“No outside guests or other staff were invited or present.
“This lasted for an hour and drinks and snacks were bought by those attending.
“He also spoke briefly to staff in the office before leaving.”
Mr Johnson had previously asked Mr Case, who has been Cabinet Secretary since September last year, to look into allegations of gatherings held in Downing Street while the public faced challenging measures to stop them from mixing.
The inquiry was then expanded and it was confirmed Mr Case could look at any alleged party if he felt it was relevant.
Details of the party in Mr Case’s office were first published by the Guido Fawkes website yesterday.
SNP Westminster leader Ian Blackford had subsequently called for Mr Case to be removed from the investigation and to resign.
Both Mr Johnson and Tory chairman Oliver Dowden had said they were sure Mr Case’s investigation would find no wrongdoing.
And Mr Johnson insisted the public was more interested in other matters such as coronavirus, and suggested the media reporting on lockdown-busting parties had caused the Tories to lose the North Shropshire by-election.
He told broadcasters “what people have been hearing is just a constant litany of stuff about politics and politicians and stuff that isn’t about them”.
But Mr Blackford said: “The Prime Minister’s appointed lead investigator into the Downing Street parties has also been reported to have hosted a party in his office – whilst thousands were forced to spend the Christmas season apart as a result of necessary coronavirus restrictions. He, along with his inquiry report, must go.”
Mr Blackford said it was “vital there be an inquiry led by an independent arbitrator – someone who owes the UK Government nothing”, and in a letter to the PM suggested it should be judge-led.
In his letter, he said: “Put simply, the public suspected this was a rigged, limited internal investigation and an attempt to dodge accountability. They now know that the person appointed by you to investigate was also involved.”
Labour’s deputy leader Angela Rayner said: “With each revelation, there is more evidence of a culture of turning a blind eye to the rules. Labour made it clear the person leading the investigation should be uncompromised, free to make an independent judgement. That’s now in serious doubt.”
The newly alleged gathering brings the total number reported to 10.
This includes the claim at the centre of the rule-breaking allegations that a party was held for Downing Street staff on December 18.
Officials and advisers reportedly made speeches, enjoyed a cheese board, drank together and exchanged Secret Santa gifts, although the Prime Minister is not thought to have attended.
Mr Johnson’s spokeswoman Allegra Stratton quit after being filmed joking about it with fellow aides at a mock press conference.
The event was at the heart of the investigation ordered by the Prime Minister.
The Department for Transport admitted a “socially distanced gathering in the large open-plan office” was held on December 16.
And Tory London mayoral candidate Shaun Bailey has apologised “unreservedly” for attending a gathering at Conservative Campaign Headquarters (CCHQ) organised by staff on his campaign team on December 14.
The Department for Education has also acknowledged a gathering on December 10.
On December 15, the Prime Minister appeared on contestants’ screens at a quiz, but insisted he broke no rules.
A published image shows the Prime Minister flanked by colleagues, one draped in tinsel and another wearing a Santa hat, in No. 10.
Downing Street admitted Mr Johnson “briefly” attended the quiz after the photographic evidence emerged, but insisted it was a virtual event.
There are allegations the Prime Minister’s then-fiancee Carrie Johnson hosted parties in their flat, in what would also have been a breach of Covid guidance, with one such event said to have taken place on November 13 – the night Dominic Cummings departed No. 10.
The Prime Minister was alleged not to have attended the alleged No. 10 flat party, but was reported to have given a farewell speech to an aide on November 27, while the lockdown in England was still in place.
And on May 15 last year, Mr Johnson reportedly spent around 15 minutes with staff in the Downing Street garden, telling one aide they deserved a drink for “beating back” coronavirus.
Earlier, party chairman Mr Dowden said he was “confident” that Mr Case’s inquiry into alleged Covid rule-busting parties would “vindicate” Mr Johnson’s assertion that no restrictions were breached.
He told BBC Radio 4’s Today programme: “I understand and I appreciate that there was a perception, particularly from the media coverage surrounding those alleged events, that we were not abiding by the rules.
“I have to say to you that there is an ongoing inquiry by the Cabinet Secretary and I’m confident that that inquiry will vindicate the Prime Minister’s assertion that everything that happened was within the rules.”