An image obtained by the Sunday Mirror shows the prime minister sitting with two colleagues underneath a portrait of Margaret Thatcher as he reportedly read out questions to staff over video.
Sources told the newspaper the quiz was held on 15 December, while London was under tier 2 restrictions which banned social mixing. Staff were invited to take part online but dozens reportedly chose to do so from No 10 instead.
One insider told the Sunday Mirror that in one office four teams made up of six people attended the quiz while huddled round computer screens.
Under Covid regulations in place in London and most other parts of the country at the time, gatherings of two or more people indoors were banned unless “reasonably necessary for work”.
Official guidance 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.”
Adam Wagner, a lawyer, tweeted that the details reported suggested “a clear breach of the govt’s guidance and a potential breach of the law, including by the PM”.
He added: “The image of the PM is of him together with two other people taking part (in fact, hosting) a social quiz at a time when gatherings of more than 1 person indoors were banned unless ‘reasonably necessary for work’ or some other exception and I can’t see any other that could apply. This appears to have been organised as a Christmas party.”
A source told the Sunday Mirror the quiz finished at 9pm but staff stayed on for two hours drinking and talking, some of them mingling in each other’s offices.
The source said: “Nobody ever questioned whether this was against the rules or if we shouldn’t be doing this.
“We all just went ahead and did it. At the time we didn’t even click that what we were doing was so severely wrong. I’ve realised now that it was actually pretty outrageous.”
The event is said to have taken place only three days before an alleged rule-breaking Christmas party in No 10, which is currently being investigated by cabinet secretary Simon Case.
The Labour deputy party leader Angela Rayner said: "While the rules said that people shouldn't have Christmas parties at work and Britons across the country were doing the right thing, Boris Johnson was instead happy to preside over a culture of disregard for the rules at the heart of government.
“Despite repeated denials of parties in No 10, it now transpires that there were numerous parties, gatherings and the prime minister even took part in a festive quiz.
“Boris Johnson really believes it's one rule for him, another for everyone else. He is a man unfit to lead this country.”
A No 10 spokesperson said: “This was a virtual quiz. Downing Street staff were often required to be in the office to work on the pandemic response so those who were in the office for work may have attended virtually from their desks.
“The prime minister briefly took part virtually in a quiz to thank staff for their hard work throughout the year.”
It was also reported that minister Therese Coffey’s staff made a habit of drinking alcohol late into the night in her office at the Department for Work and Pensions (DWP) while the rest of the country stayed at home under Covid-19 lockdown restrictions.
According to the Sunday Mirror, DWP staff and officials would also order takeaway food to her office and, on one occasion, Ms Coffey, secretary of state for work and pensions, handed round Christmas presents.
The DWP said that, although the drinking was happening after work hours, the staff were still working at the time.
But one source said: “Even during lockdown, there were parties all the time.” Another added: “There is a constant flow of booze in the office.”
A DWP spokesperson told The Independent: “Throughout the pandemic, DWP officials have followed government guidance while continuing to deliver vital services for millions of people.
“Staff worked from home where possible but a core team working directly to the secretary of state regularly worked from the office, in accordance with the Covid-19 rules as they evolved.
“The team regularly worked late into the evening and on a number of occasions they ate takeaway food and drank some alcohol.
“On one occasion close to Christmas, the secretary of state gave gifts to her core team, as she does every year.”
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