Boris Johnson is willing to be interviewed by the Metropolitan Police for a probe into alleged rule-breaking parties, Downing Street has said.
The Prime Minister was informed that Met Police Commissioner Dame Cressida Dick would announce that she was launching an inquiry into the 'partygate' saga this morning.
But he failed to inform top ministers during this morning's Cabinet meeting - and they were in the dark until the end of the meeting at 10.30am, as they didn't have their phones.
Half an hour earlier, Dame Cressida told London Assembly members that the force would finally look into "a number of events" in Downing Street and Whitehall during the pandemic.
It is understood that top civil servant Sue Gray will now pause investigating any events which are being looked into by police.
However, No10 said Ms Gray could continue investigating - and could still publish a report - on any events police have decided not to investigate.
The move throws the Tory party into further chaos as dozens of MPs were waiting until Sue Gray's report before deciding whether to try to topple Boris Johnson. But now her report may only be a partial summary.
Mr Johnson told MPs he "welcomes the Met's decision to conduct its own investigation because I believe this will help to give the public the clarity it needs and help to draw a line under matters".
Downing Street said the PM thinks it is "entirely right" for the Metropolitan Police to investigate.
Asked if the PM would submit himself to questioning, the PM's official spokesman said: "Anyone who is required to would be expected to cooperate in any way they are asked to."
Pressed again, the spokesman said: "Anyone asked to will cooperate fully, as you would expect."
Asked if the PM thought he would be vindicated by the probe, the spokesman said: "I don't think it would be wise for anyone to prejudged the investigation publicly like that.
"You have seen the PM's previous comments on this. He believes that this work will help provide further clarity and help draw a line under this."
Asked if the PM thought he had broken the law, the PM's spokesman said: "I need to be cautious about what I say.
"I think it’s fair to say that he does not, but obviously beyond that I do not want to pre-empt the work of the police."
No10 suggested diaries, phones and other documents could be handed over, saying: "That’s always been the case that we have sought to provide any requisite information to the investigation, and that sort of co-operation will continue."
Yet No10 said Mr Johnson did not discuss the police probe at Cabinet, despite being informed in advance.
The PM's spokesman said: "That was confirmed by the police while Cabinet was taking place so he didn't reference it specifically, he alluded to that at the end of Cabinet but beyond that, no.
"He made those comments about ensuring the Government is not deterred from getting on with the job, he didn't go into detail about the Met given that Cressida Dick made her comments while Cabinet was taking place."
Mr Johnson was "made aware shortly before" the Met Police chief made the announcement - and before the Cabinet session began, the spokesman said.
No10 would not say whether Mr Johnson considered being fined for Covid rule breaches - or being interviewed by police under caution - would be a resigning matter.
Labour's Angela Rayner warned the public have "made up their minds" about the Prime Minister.
The Deputy Labour leader told the Commons: "Just weeks ago the Prime Minister told this House, 'there was no party'. How does the Paymaster General explain that?
"I know across the country people know enough. They have made up their minds about the Prime Minister. When will his party catch up?"
Tory Minister Michael Ellis said: "The government recognises and I recognise the public anxiety, and indignation that it appears as though the people who have been setting the rules may not have been following, and I would like to repeat that sentiment today.
"There is a limit to what I can say given this is an ongoing investigation and an ongoing police investigation."
Liberal Democrat leader Sir Ed Davey called for Mr Johnson to resign.
He said: "It's clear the Government is now in total meltdown. Story after story about Covid laws being broken in No10, revelations about MPs having constituency funding threatened by government whips, and now a Prime Minister and his staff under police investigation."
The Met had been under pressure to launch an investigation for weeks, with the Daily Mirror first reporting allegations of parties in No 10 during Covid restrictions two months ago.
Fresh allegations have emerged at a steady pace since then and have now totalled at least 19 separate events.
The latest emerged on Monday when Downing Street was forced to admit Mr Johnson had a birthday celebration inside No 10 during the first lockdown.
Downing Street conceded staff "gathered briefly" in the Cabinet Room following a meeting, after it was alleged 30 people attended and shared cake despite social mixing indoors being banned.
ITV News reported the Prime Minister's wife, Carrie Johnson, had organised the surprise get-together complete with a chorus of "happy birthday" on the afternoon of June 19 2020.
Interior designer Lulu Lytle admitted attending but insisted she was only present "briefly" while waiting to talk to Mr Johnson about the lavish refurbishments she was carrying out to the couple's flat above No 11.
Chancellor Rishi Sunak was understood to have briefly attended as the gathering was breaking up as he entered the room to attend a Covid strategy meeting.
ITV reported picnic food from M&S was eaten and Martin Reynolds, Mr Johnson's under-fire principal private secretary, was also said to have attended, as was No 10's director of communications Jack Doyle and head of operations Shelley Williams-Walker.
Social gatherings indoors were forbidden under lockdown laws at the time, with a relaxation of the regulations permitting gatherings of up to six people to take place outside.
No10 refused to say if the June 19 birthday gathering was "reasonably necessary for work" - as the law said gatherings should be at the time. The PM's spokesman said: "It was in between the PM returning from a visit and starting another meeting - it wasn’t a specific meeting in itself."
