Here is a list of the alleged gatherings, which in several cases have been admitted to.
- May 15 2020: Downing Street garden party
Boris Johnson, his wife 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.'
- May 20 2020: BYOB garden party
The revelation came in an email, leaked to ITV, from Mr Reynolds to more than 100 Downing Street employees inviting them to 'bring your own booze' for an evening gathering.
Multiple reports have suggested the Prime Minister attended the event with his wife.
- November 13 2020: 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 a close ally of Mr Cummings.
- November 13 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 November 13, the night Mr Cummings departed No 10.
A spokesman for Mrs Johnson has called the claim 'total nonsense'.
- November 25 2020: Treasury drinks
A Treasury spokesman told The Times that a number of staff had gone into the office to work on the Spending Review.
He said: 'We have been made aware that a small number of those staff had impromptu drinks around their desks after the event.'
- November 27 2020: 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.
- December 10 2020: Department for Education party
The DfE confirmed a social event had happened after The Mirror reported that 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'.
- December 11 2020: Wine fridge delivered to Downing Street for staff's 'wine-time Fridays'
A fridge with the capacity for 34 wine bottles was delivered through the back door of No 10.
According to sources cited by The Mirror, the fridge became necessary for staff's 'wine-time Fridays' which were held throughout lockdown, with the Prime Minister allegedly encouraging the parties to help aides 'let off steam'.
The regular social gatherings were reported to be particularly popular among staff between autumn 2020 and spring 2020 when staff were 'fatigued' with tough Covid restrictions that banned socialising.
Mr Johnson was said to have attended a 'handful' of these gatherings.
- December 14 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 judgment at a time when Londoners were making immense sacrifices to keep us all
