No10 said the Prime Minister and Chancellor were among those set to be handed fixed penalty notices (FPNs) over the partygate scandal.
The Met has now issued more than 50 fines over lockdown busting events in Downing Street and across Whitehall in 2020 and 2021.
A No 10 spokesman said: “Prime Minister Boris Johnson and Chancellor Rishi Sunak will be issued with fines for breaches of Covid-19 regulations following allegations of lockdown parties in Downing Street and Whitehall.”
Earlier this month Scotland Yard handed out an initial tranche of 20 partygate fines. The £50 penalties were sent to individuals by email.
Detectives made a further 30 fine referrals to the ACRO Criminal Records Office on Tuesday.
A Met spokesman said: “The investigation into allegations of breaches of Covid-19 regulations in Whitehall and Downing Street continues to progress.
“As of Tuesday, April 12 2022 we have made over 50 referrals for fixed penalty notices (FPNs) to the ACRO Criminal Records Office for breaches of Covid-19 regulations who following the referral issue the FPNs to the individual.
“We are making every effort to progress this investigation at speed, this includes continuing to assess significant amounts of investigative material from which further referrals may be made to ACRO [Criminal Records Office].”
The force did not disclose the names of those involved, but Helen MacNamara was reported to be among the first people to be fined for attending a lockdown karaoke party.
Ms MacNamara, who was in charge of Whitehall ethics, was allegedly part of a “raucous” leaving party for a former Number 10 aide on June 18, 2020 when indoor gatherings were banned.
Met detectives began investigating 12 events held across government in January following an internal inquiry by senior civil servant Sue Gray.
Boris Johnson is thought to have been at up to six of the gatherings.
Downing Street has said it will not confirm the identity of anyone fined as a result of the Met’s investigation, named Operation Hillman , with the exception of the Prime Minister and civil service head Simon Case.
Hundreds of photographs and pages of evidence have been handed to the Met, which has warned it has a “significant amount of investigative material” to go through.