A "bring your own booze" party in the No 10 Downing Street garden is the latest in a string of allegations of gatherings held across the UK government while coronavirus restrictions were in place.
Here is a list of what has been reported so far.
15 May 2020: Downing Street garden party
UK Prime Minister Boris Johnson, his then girlfriend Carrie, former chief adviser Dominic Cummings, and Mr Johnson's principal private secretary Martin Reynolds were all pictured, in a photograph leaked to The Guardian, sitting around a table in the No 10 garden, with wine and cheese in front of them.
Some 15 other people were also in the photograph, but the Prime Minister has insisted this was a work meeting, saying: "Those were meetings of people at work, talking about work."
20 May 2020: BYOB garden party
The latest revelation came in an email, leaked to ITV, from Mr Reynolds to more than 100 Downing Street employees asking them to "bring your own booze" for an evening gathering.
Multiple reports have suggested the Prime Minister attended the event with his future wife.
13 November 2020: A leaving party for senior aide
According to reports at the time, Mr Johnson gave a leaving speech for Lee Cain, his departing director of communications and close ally of Mr Cummings.
13 November 2020: Johnsons' flat party
There are allegations that the Prime Minister's then fiancee hosted parties in their flat, with one such event said to have taken place on 13 November, the night Mr Cummings departed No 10.
A spokesman for Carrie Johnson has called the claim "total nonsense".
25 November 2020: Treasury drinks
A Treasury spokesperson told The Times a number of staff had come into the office to work on the Spending Review.
They said: "We have been made aware that a small number of those staff had impromptu drinks around their desks after the event."
27 November 2020: A second staff leaving do
The Mirror reported that the Prime Minister gave a farewell speech to an aide at the end of November while the lockdown in England was still in place.
Other reports have said the leaving do was for Cleo Watson, a senior Downing Street aide and ally of Mr Cummings.
10 December 2020: Department for Education party
The Department for Education confirmed a social event had happened after The Mirror reported former education secretary Gavin Williamson threw a party and delivered a short speech at an event organised at his department's Whitehall headquarters.
A spokesman acknowledged that "it would have been better not to have gathered in this way at that particular time".
14 December 2020: Party featuring Tory London mayoral candidate Shaun Bailey and staff
Shaun Bailey apologised "unreservedly" for attending the gathering at Conservative Campaign Headquarters (CCHQ) organised by staff on his campaign team.
"It was a serious error of judgement at a time when Londoners were making immense sacrifices to keep us all safe and I regret it wholeheartedly," he tweeted.
He quit his role chairing the London Assembly's police and crime committee after The Mirror published a picture showing him at the gathering.
15 December 2020: Downing Street quiz
The Prime Minister appeared on contestants' screens at the quiz but insisted he broke no rules.
An image published by the Sunday Mirror showed Mr Johnson flanked by colleagues, one draped in tinsel and another wearing a Santa hat, in No 10.
Downing Street admitted Mr Johnson "briefly" attended the quiz after the photographic evidence emerged but insisted it was a virtual event.
16 December 2020: Department for Transport party
The Mirror reported senior civil servants were "boozing and dancing" at the event, allegedly planned by staff from Transport Secretary Grant Shapps' office.
A Department for Transport spokesman said: "Fewer than a dozen staff who were working in the office had a low-key, socially distanced gathering in the large open-plan office after work on December 16, where food and drink was consumed. We recognise this was inappropriate and apologise for the error of judgement."
17 December 2020: Cabinet Office 'Christmas party!'
A number of outlets reported that a gathering was held in the Cabinet Office on 17 December.
The Times reported that Cabinet Secretary Simon Case attended the party in room 103 of the Cabinet Office, that it had been organised by a private secretary in Mr Case's team, and that it was included in digital calendars as "Christmas party!".
The Cabinet Office confirmed a quiz took place, but a spokesperson said: "The Cabinet Secretary played no part in the event, but walked through the team's office on the way to his own office."
18 December 2020: Christmas party at Downing Street
The claim which kicked off the rule-breaking allegations is that a party was held for Downing Street staff on 18 December.
Officials and advisers reportedly made speeches, enjoyed a cheese board, drank together and exchanged Secret Santa gifts, although the Prime Minister is not thought to have attended.