Live Updates: Boris Johnson and U.K. Lockdown Report News

The report explores 16 gatherings that took place from May 2020 to April 2021, and, for the first time, lays out in stark detail the evidence of rule-breaking at the highest level of government in allowing questionable events to take place in Downing Street when the rest of Britain was under lockdown.

A pattern of booze-fueled parties at Downing Street was also described in the report — some that involved karaoke, music, and dozens of people — even as the public at large was being told not to gather with people from other households, including relatives. At the time, hospitals and nursing homes were also discouraging or prohibiting visitors, and funerals were allowed only with very limited attendance.

The details of the parties reflected what Ms. Gray’s inquiry called “failures of leadership and judgment in No. 10 and the Cabinet Office.” Photographs from the gatherings, along with emails, messages and accounts of the parties were also included in the report.

A party on June 18, 2020, at Downing Street and in the Cabinet Office at 70 Whitehall, for example, involved speeches, alcohol, food and music. At least one person got sick and there was at least one fight; the last member of staff didn’t leave until after 3 a.m.

That party, which took place in two stages, included more than 25 people who had gathered to say goodbye to a departing colleague and featured speeches in the Cabinet Room. Dominic Cummings, a special adviser to Prime Minister Boris Johnson; and Simon Case, the permanent secretary for Covid and the pandemic response, attended that event.

A series of other parties, around Christmas 2020, also came under the spotlight, revealing instances of more drunkenness in government offices.

One of the parties, on Dec. 18, 2020, was an hourslong, planned event at the press office at Downing Street, with 20 to 45 people congregating to celebrate Christmas and the end of the year. The gathering included a Secret Santa game, an awards ceremony, alcohol and food. According to the report, “Some members of staff drank excessively. The event was crowded and noisy,” with staff members staying until after midnight. A cleaner cited in the report described red wine having been spilled on the floor.

At the time, gatherings of two or more people from different households were prohibited. Weeks later, on Jan. 14, 2021, while the same restrictions were in place, a goodbye event for two officials at Downing Street took place. It involved alcohol, and Mr. Johnson attended for a short time to give a speech, while others stayed late into the evening.

Two more gatherings were held at Downing Street on April 16. At that time, restrictions had slightly eased but nonwork gatherings of two or more households indoors or six outdoors were still prohibited. Both events lasted for hours, the report said, with senior officials attending, though Mr. Johnson was not there.

“A number of those present drank excessively,” the report added. After more than 20 people moved outside, still drinking, they damaged a child’s play set, and the last staff members left after 4 a.m.

Emails and messages detailed in the report showed that some people had expressed reservations about gathering while the restrictions were in force. But others seemed to simply ignore the warnings as they exchanged invitations to the parties.

The report included a series of emails sent before a gathering on May 20, 2020, organized by officials to bolster morale and attended by 30 to 40 members of staff in the garden of 10 Downing Street.

Lee Cain, who was then the director of communications for Mr. Johnson’s office, received an invitation and sent a response back to other officials saying, “I’m sure it will be fine — and I applaud the gesture — but a 200 odd person invitation for drinks in the garden of no 10 is somewhat of a comms risk in the current environment.” According to the report, his concerns and those raised by other senior members of staff were ignored.

Mr. Johnson attended the May 20 party for about 30 minutes, the report said. Later, his principal private secretary at the time, Martin Reynolds, texted another adviser in a message about the news media that read, “better than them focusing on our drinks (which we seem to have got away with).”