Boris Johnson is facing fresh questions after photos apparently show the prime minister drinking at a party during a Covid lockdown.
The pictures, released by ITV News, are believed to show the prime minister at a leaving party on 13 November 2020.
Asked in Parliament in December whether the gathering had taken place, Mr Johnson denied it had and said all rules were followed.
The Metropolitan Police are also facing calls to explain why he was not fined.
The BBC has been told that at least one person who attended the event was fined, but the PM was not.
Meanwhile, civil servant Sue Gray’s report into No 10 parties is imminent, a Downing Street source said.
The police watchdog has been urged to review the force’s handling of the Partygate investigation.
A raft of allegations about gatherings held in Downing Street and Whitehall throughout the pandemic led to a Metropolitan Police investigation into 12 events.
The inquiry concluded last week, with a total of 126 fixed penalty notices being issued to 83 individuals for parties held over eight separate dates.
Mr Johnson, his wife Carrie, and Chancellor Rishi Sunak all received one fine each for attending a birthday party thrown in the PM’s honour in June 2020.
But No 10 confirmed the PM was not facing any additional fines from the police.
The prime minister and the Met are under fresh scrutiny after ITV News published four new photographs on Monday which it says were taken at the leaving do for Mr Johnson’s communications chief, Lee Cain on 13 November 2020.
Mr Johnson is pictured toasting colleagues while standing by a table laden with wine bottles, wine glasses, food and other drinks.
A second coronavirus lockdown was in place in England at the time the photographs were taken, with indoor gatherings of two or more people banned, except if “reasonably necessary” for work purposes.
The emergence of the photographs has sparked fresh claims from opposition MPs and others that Mr Johnson knowingly misled Parliament when he previously told them no Covid rules had been broken in Downing Street.
On 8 December 2020, Labour MP Catherine West asked Mr Johnson in the Commons if a party had taken place in Downing Street on 13 November – though it is not clear if she was referring to the event photographed.
The PM replied: “No, but I’m sure whatever happened the guidance was followed and all the rules were followed at all times.”
The prime minister faces a probe by the Commons’ Privileges Committee about whether he lied to MPs. Under government guidelines, ministers who knowingly mislead Parliament are expected to resign.