Scotland Yard has referred itself to the Independent Office for Police Conduct (IOPC) after concerns were raised over its response to the December 18, 2020 event and its lack of an investigation.
It is understood the IOPC will make a decision before the end of the week.
Green Party peer Baroness Jones of Moulsecoomb initially wrote to the watchdog to make a complaint, with the Met replying to her to confirm it has been split into two parts.
Lady Jones has argued there is a “case to answer” for the Met “aiding and abetting a criminal offence, or deliberately failing to enforce the law in favour of Government politicians and their staff” due to the “extensive” police presence in Downing Street.
In her complaint letter, she added: “If there was an unlawful gathering taking place at Number 10 Downing Street, then the police must have known, and were highly likely to have played an active part in organising or facilitating the illegal gathering.”
Acting Detective Chief Superintendent Tony O’Sullivan, directorate of professional standards, told Lady Jones this has been referred to the IOPC given “you effectively allege misconduct in public office by MPS police officers”.
“The IOPC will now make a determination as to whether the complaint needs to be investigated and, if so, how.”
On the second part, a Met inspector said it relates to Lady Jones’s complaint that Met Commissioner Dame Cressida Dick has “refused to investigate allegations of an unlawful gathering on December 18, 2020″.
This has been referred to the Mayor’s Office for Policing And Crime (Mopac), which sets the direction and budget for the Met.
Both the IOPC and Mopac have confirmed they are assessing the complaints to decide if further action is required.
It is alleged a Christmas party in Downing Street on December 18 last year saw officials and advisers make speeches, enjoy a cheese board, drink together and exchange Secret Santa gifts, although the Prime Minister is not thought to have attended.
Boris Johnson’s spokeswoman Allegra Stratton quit after being filmed joking about it with fellow aides at a mock press conference.