The Met Police faces fresh calls to investigate a No 10 "virtual" Christmas quiz after a new picture emerged of Boris Johnson with an open bottle of bubbly.
The image shows the Prime Minister flanked by three members of staff, one wearing tinsel and another a Santa hat, at the event on December 15, 2020.
On the desk in front of him - from where he read out quiz questions to teams across the building - is what appears to be champagne and a half-eaten packet of crisps.
Mr Johnson was accused of personally breaking Covid laws by hosting the festive event after the Mirror revealed last year that it had taken place.
At the time London was under Tier 2 regulations banning any social mixing between two or more people from different households.
Official guidance also stated: “You must not have a work Christmas lunch or party, where that is a primarily social activity and is not otherwise permitted by the rules in your tier.”
Just two days after the Mirror's initial story, the PM said: “I can tell you once again that I certainly broke no rules."
But the Christmas quiz is not one of the dozen No 10 gatherings under investigation by police.
This is despite a smaller festive quiz held in the Cabinet Office just two days later being looked at.
One Covid laws expert said that Scotland Yard should now add the Downing Street Christmas quiz to the list of events it is probing.
Barrister Adam Wagner told The Mirror: "The previous photograph of the Prime Minister showed what could have been a meeting briefly interrupted by a Zoom call.
"However, the new photograph shows four people with alcohol and food, as well as a Christmas hat and tinsel, which suggests a Christmas party.
"This was held at a time when indoor social gatherings of two or more people were banned and the Government had told people they "must" not have a Christmas party."
The top lawyer added: "In light of the new evidence it now makes no sense for this gathering not to be investigated by the police given that an almost identical gathering in the Cabinet Secretary Simon Case's office two day's later is being investigated."
In the new image, Mr Johnson appears to be putting a badge on his suit jacket.
Later that evening, No 10 pins were distributed to Downing Street staff as a Christmas present from the PM.
Downing Street has insisted the event was a “virtual quiz”, but admitted “those who were in the office for work may have attended virtually from their desks.”
Labour MP Fabian Hamilton raised the photo in PMQs - and contrasted the merriment to a constituent who was unable to have visits from her family while having cancer treatment.
He said: "For the sake of my constituent and the sacrifices she made, will the PM be referring this party to the police as it's not one of the parties being investigated?"
But the PM hit back, saying: "He is completely in error."
He later said the event "had been submitted for investigation".
Former No10 aide Dominic Cummings warned: "There's waaaaay better pics than that floating around, incl in the flat."
No10 pointed out the event itself had already been considered by Scotland Yard, which decided not to investigate it further.
But the PM’s Press Secretary could not say whether the newly-revealed photo had been sent to the Met, saying: “I’m not aware of that and it wouldn’t be appropriate for me to comment”.
Of Sue Gray, the Press Secretary added: “She has had access to all information that is relevant and required.”
Asked what was happening in the picture, she said: "We've talked about this one before, it is a virtual quiz."
The Mirror revealed last year that dozens of staff had spent the evening huddling in groups around their office computers rather than dialling in from home.
In one office, the insider said, there were four teams, each made up of six people.
Sources said staff had knocked back fizz, wine and beer - and some stayed in Number 10 socialising and drinking for hours after the quiz finished at 9.30pm.
Team names included "Professor Quiz Whitty", "Next Slide Please", "We've Been Clear”, “The 6 Masketeers” and "Hands, Face, First Place" - a reference to the slogan introduced to encourage social distancing and mask wearing.
The Mirror also revealed an email showing organisers had planned days in advance for some staff to enjoy the quiz in person, from the office.
A senior official even urged staff, including teams from the PM's private office, the policy unit and the press office, to leave No 10 through the back door at the end of the night.
Mr Johnson has spent the last few days trying to shore up support after mass resignations from No 10 last week raised further questions about his authority.
Downing Street is hoping his "defensive" mini-reshuffle to promote loyalists - and the promise of a bigger reshuffle in early summer - will be enough to keep mutinous Tory MPs at bay.
But many Tories are privately saying they are waiting for the result of the Met investigation and the full Sue Gray report to decide whether to trigger a confidence vote.
The PM's allies have claimed that he will not resign even if he is fined by the Metropolitan Police for breaching Covid rules.
One former Cabinet minister told the Mirror: “If Sue Gray finds he lied to parliament unequivocally, or depending what action police take - that’s it.
"Either of those two things would be terminal."
