Westminster sources suggest the Met Police will issue at least 15 fines for rule breaches initially.
The first fines for breaches of Covid-19 rules as part of a police investigation into government lockdown parties will be issued soon, the BBC has been told.
Westminster sources suggested the force will issue at least 15 fines initially.
The Metropolitan Police investigation into 12 events held across government was launched in late January.
It came after an internal inquiry passed information to the force. The Guardian said fines were “imminent”.
The Met has not commented and Downing Street has been approached for comment.
Government sources told the BBC the Met could issue the fines on Tuesday.
The Met said it would contact people “believed to have taken part in the events in question to get their accounts”.
The force had sent questionnaires to dozens of staff members, aides and ministers, including Prime Minister Boris Johnson and Chancellor Rishi Sunak.
For months, the prime minister and his government were dogged by reports of staff parties in Downing Street when Covid-19 restrictions were in place.
Officers have already been supplied with more than 300 photographs and 500 pages of material, from a separate inquiry led by senior civil servant Sue Gray.