Sue Gray report: Boris Johnson's adviser boasted ‘we seem to have got away with’ BYOB party

Then-principal private secretary Martin Reynolds arranged a gathering in the No 10 garden on May 20, 2020 when leaving home without a reasonable excuse was banned.

Sue Gray’s partygate inquiry found some individuals expressed concern over whether it was right to hold the event but it went ahead all the same.

An email on behalf of Mr Reynolds was sent inviting around 200 staff to enjoy the “lovely weather” with some “socially distanced drinks in the garden this evening”.

A police officer knocks on the door of the Prime Minister's official residence in Downing Street. Picture: PA

“Please join us from 6pm and bring your own booze!” the email said.

Then-No 10 communications director Lee Cain emailed Mr Reynolds saying “I’m sure it will be fine – and I applaud the gesture”.

But he acknowledged it represented “somewhat of a comms risk in the current environment”.

Ms Gray struggled to ascertain how many people attended, but estimated it was around 30 to 40 people, including for around 30 minutes the Prime Minister.

“Drinks and pizza” provided and paid for by staff were enjoyed, the senior civil servant’s report said, with a number of staff leaving between 10pm and 11pm.

The following day, a No 10 special adviser thanked Mr Reynolds for “providing the wine”, saying it was “a very kind thing to do and I know everyone really appreciated it”.

Dubbed “Party Marty” after reports of the invite emerged, Mr Reynolds was subsequently forced out amid outrage over the partygate scandal.

He is reportedly being lined up to become the UK’s next ambassador to Saudi Arabia.