No 10 has confirmed that the Prime Minister and the Chancellor are to be fined for attending the gatherings, which broke regulations imposed by their own Government.
The Prime Minister’s wife, Carrie Johnson, has also been told she will receive a fine.
It comes after the Metropolitan Police announced 30 additional fines today (Tuesday, April 12) in relation to Operation Hillman, the ‘Partygate’ probe dealing with alleged breaches by some of the UK’s most senior political figures.
A No 10 spokesman said: “The Prime Minister and Chancellor of the Exchequer have today received notification that the Metropolitan Police intend to issue them with fixed penalty notices.
“We have no further details, but we will update you again when we do.”
Labour leader Sir Keir Starmer said both Mr Johnson and Mr Sunak should quit following the confirmation.
Sir Keir said: “Boris Johnson and Rishi Sunak have broken the law and repeatedly lied to the British public.
“They must both resign. The Conservatives are totally unfit to govern. Britain deserves better.”
More than 50 referrals for fines have now been made, said the Met in its latest update, up from 20 it said were made at the end of March.
Scotland Yard said it was “making every effort to progress this investigation at speed” and said there is a possibility of more fines to come.
The force has not named those facing fines, citing traditional practices when dealing with out-of-court matters such as speeding fines, but Downing Street said it would confirm if Mr Johnson was among those being penalised.
Mr Johnson is understood to have been present at six of at least 12 events that are being investigated by the Met.
Liberal Democrat leader Sir Ed Davey said the new batch of fines “expose the shocking scale of the criminality in Boris Johnson’s No 10”.
He said: “The police have completely shredded Johnson’s claims that no laws were broken.
“He cannot be trusted and cannot continue as Prime Minister.”
Labour deputy leader Angela Rayner added: “This is just the latest example of a distracted out-of-touch government, guilty of breaking the law never mind enforcing it.”