LONDON (BLOOMBERG) - Britain's Prime Minister Boris Johnson, engulfed by a string of crises that have angered Tory lawmakers, could face more ire over a report that he personally breached Covid-19 lockdown rules a year ago.

The Mirror reported on Saturday (Dec 11) night that the prime minister hosted a Christmas quiz from his Downing Street residence on Dec 15 last year, when London was under a "no mixing" order.

The prime minister was pictured on screen with at least two aides as he read out questions to staff, who participated via computer from their offices at No. 10 in teams of up to six people.

London at the time was under regulations that banned social mixing between households. Christmas work gatherings were prohibited.

“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,” a spokesperson for No. 10 said on Sunday. 

“The Prime Minister briefly took part virtually in a quiz to thank staff for their hard work throughout the year.”

The Mirror reported that staff had been invited weeks earlier to participate in a virtual quiz to raise money for charity.

Mr Johnson's popularity has slumped in recent weeks after the botched handling of an ethics probe and as the government proposed harsh new "Plan B" restrictions to thwart a new surge in Covid-19 cases as well as the fast-spreading Omicron variant.

The Labour Party raced to a six-point lead over Mr Johnson's Conservative Party in a Savanta ComRes poll for the Daily Mail taken from Dec 9 to 10, a nine-point swing from Dec 3 to 5.

Parliament is expected to vote this week on the latest restrictions and Mr Johnson could face a rebellion of about 60 Tory lawmakers, according to people who spoke on condition of anonymity.

The question of whether the string of controversies marks the beginning of the end for Mr Johnson is now being openly debated, even in Tory-friendly papers.

Last week, Mr Johnson faced allegations that a Christmas party was held in Downing Street in 2020 that breached Covid-19 restrictions at the height of the pandemic. Video was also leaked showing his staff making light of Covid-19 measures.

The prime minister has so far said he was not involved in social gatherings at his residence last Christmas. In Parliament last week, Mr Johnson said he had been "repeatedly assured" that no Covid-19 rules were broken.