Downing Street has denied claims that Boris Johnson broke coronavirus rules with parties at No 10 last Christmas.
The Mirror claims the PM made a speech at a leaving do on 13 November – when the country was in the second lockdown – and allowed a festive party to proceed on 18 December when London was in the grips of Tier 3 restrictions.
A No 10 spokesperson told Sky News: “COVID rules have been followed at all times.”
The original story claimed Mr Johnson did not attend the event in December held by members of his top team.
A spokeswoman for the PM’s wife Carrie Johnson denied she hosted the bash or held any parties at the flat while restrictions were in place.
“This is total nonsense. Mrs Johnson has followed coronavirus rules at all times and it is categorically untrue to suggest otherwise,” she told the Mirror.
Responding to the newspaper’s original story, Labour said “one rule for them, another for everyone else”.
The Mirror alleges that around “40 or 50” people were crammed “cheek by jowl” into a room in Number 10 for both events.
Last November, the whole country was plunged into a second national lockdown for four weeks.
As a result, everyone was told to work from home where possible and indoor socialising was banned.
At the start of December 2020, London was in Tier 2 restrictions, which meant no household mixing indoors.
But on 16 December, two days before the second Downing Street bash allegedly took place, London moved into Tier 3 restrictions where all indoor mixing was banned unless individuals were in household bubbles.
Downing Street staff are classified as key workers and have been throughout, with members working long hours to deal with the pandemic.
The offices are said to be COVID-secure.
The revelations come after the PM on Tuesday rejected the idea that Christmas parties should be scrapped due to the new Omicron variant.
Earlier, top health chief Dr Jenny Harries had warned that people should cut down on socialising during the festive period to curb future COVID infections.
Ms Harries said everyone can do their bit by reducing the number of social contacts they have – and by “not socialising when we don’t particularly need to”.
But the PM rejected Dr Harries’ call, insisting that he had already put in place a package of “balanced and proportionate measures” in response to the threat posed by the new Omicron variant.
Speaking at a Downing Street news briefing, Mr Johnson said: “We don’t want people to cancel such events and we think that, overwhelmingly, the best thing for kids is to be at school, as I have said many times throughout this pandemic.
“What we are doing is trying to take a balanced and proportionate approach to the particular risk that seems to be posed by Omicron – certainly is posed by Omicron – focused, in particular, on measures at the border.”
Her comments caused alarm among many Conservative MPs who later raised their concern in the Commons.
One former Conservative minister, Steve Baker, said the government was “facing chaos” following Ms Harries’ comments.