Gatherings in Whitehall throughout the pandemic involved “excessive drinking”, broken swings for children and fights between staff, according to details revealed in Gray’s report.

At the December 18 event, which took place in Press Office No. 10 and was attended by between 20 and 45 people, Gray noted a rowdy atmosphere where people drank “to excess.”

“The event was crowded and noisy, so some people working elsewhere in building #10 that evening heard significant noise levels from what they described as a party in the press office,” she wrote.

“A cleaner who visited the room the following morning noted that there had been spilled red wine on a wall and on a number of boxes of photocopier paper,” the report said.

Two rallies took place on June 18, 2020, the report notes. The first, which took place at No. 10 in the Cabinet Room, lasted up to an hour. The second, which took place at 70 Whitehall in the Cabinet Secretary’s apartments, involved “alcohol, food and music” and lasted several hours.

Helen MacNamara, Deputy Cabinet Secretary, attended part of the evening and even provided a karaoke machine, the report added.

“There was excessive drinking in some people,” she said. “An individual was sick. There was a minor altercation between two other individuals.

At the gathering on April 16, 2021, the day before Prince Philip’s funeral, the report details how the staff partied into the wee hours of the morning.

“Exit logs indicate that some left after midnight and others between 01:45 and 02:45. Two members of staff stayed even later, one leaving at 03:11 and the last leaving at 04:20.

However, Gray says it was ‘not appropriate or proportionate’ to investigate the gathering in the flat on November 13, 2020, as the Metropolitan Police had begun work on their separate investigation into the breach of the rules in Whitehall .

“Information gathered on this gathering is limited as the evidence gathering process had only just begun when the Metropolitan Police announced their own investigations, which included events on November 13, 2020,” she said.

“At this point, I have stopped my investigation, given the need to avoid any prejudice to the police investigation.”