Downing Street party: What were the Covid rules at the time?

Prime Minister Boris Johnson has apologised for a video where senior No 10 staff joked about holding a Christmas party last December.

Mr Johnson says he was "repeatedly assured that the rules were not broken" and has ordered an investigation into exactly what happened.

The Daily Mirror first reported last week that a party took place in Downing Street last December.

Downing Street insisted no party took place and that "Covid rules have been followed at all times". A number of ministers appeared on television and radio to repeat the denials.

But a source has confirmed to the BBC that there was a party on 18 December, with "several dozen" people in attendance.

A video - obtained by ITV News - shows a recording of a rehearsal on 22 December for Downing Street's proposed media briefings.

In the video, the prime minister's then-press secretary Allegra Stratton is asked by colleagues about reports of a party. She jokes: "This fictional party was a business meeting and it was not socially distanced."

Ms Stratton has resigned and said she would "regret the remarks for the rest of my days".

The prime minister has asked Cabinet Secretary Simon Case to investigate the party. Downing Street has declined to comment on whether he attended it.

And at a government briefing Boris Johnson said: "To the best of my knowledge we have followed the rules throughout."

Any party at Downing Street would have breached the government's guidelines at the time.

Its guidance for the Christmas period specifically said: "Although there are exemptions for work purposes, 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."

This same line was also tweeted out by the official gov.uk account on 17 December 2021 in response to a question about whether Christmas parties were allowed in the workplace.

London at the time was in Tier 3 (it went into Tier 4 on 21 December) and the law banned gatherings of two or more people indoors unless it was "reasonably necessary" for work.

There was also a specific prohibition on organising an indoor gathering of more than 30 people.

But there may have theoretically been a legal loophole for government buildings like 10 Downing Street because of the 1984 legislation used to bring in the tier system, according to Adam Wagner - a barrister at Doughty Street Chambers and an expert on Covid regulations.

Another barrister, Charles Holland from Trinity Chambers, tweeted that there would have needed to be an agreement with Westminster City Council for the regulations to apply in Downing Street.

We have asked Westminster City Council to confirm whether this was the case, but they have yet to respond.

There are multiple reports of another party taking place on 27 November, which is understood to have been a leaving party for Cleo Watson, a former aide to Dominic Cummings.

Boris Johnson is reported to have made a speech at that event, mentioning how crowded it was in the room.

At that point there was still a national lockdown in force, which ended on 2 December. Indoor gatherings were also not allowed in lockdown.

Several sources have told the BBC about a Christmas quiz that took place at Downing Street around the same time as the 18 December party, with some people participating virtually but other groups present in person.

And the Department for Education has said of a gathering for staff in December 2020 with drinks and snacks that "we accept it would have been better not to have gathered in this way at that particular time".

The cabinet secretary will also be investigating the DfE party.

Thousands of of people were fined for breaking rules on gatherings last year, according to figures from the National Police Chiefs' Council.

Between March 2020 and January 2021:

At the time, large parties could be shut down by the police - with fines of up to £10,000. Examples include:

What claims do you want BBC Reality Check to investigate? Get in touch

Read more from Reality Check