Boris Johnson reportedly attended Downing Street lockdown party in May 2020

It has been alleged that Boris Johnson attended a party with No 10 staff during the first national lockdown in May last year.

It comes as the former Conservative mayoral hopeful Shaun Bailey quit as chairman of the London Assembly’s Police and Crime Committee on Tuesday.

His resignation as chairman of the committee came shortly before The Mirror published a photograph of him and other staff at a party in Conservative headquarters.

The image showed 24 people with drinks, and buffet food laid out.

The Tories previously admitted the party had taken place on December 14, when London was in Tier 2 restrictions, and said that staff had been disciplined.

The Guardian and The Independent reported that Boris Johnson was present for 15 minutes at the gathering said to have taken place on May 15 2020, following a Covid press conference.

The newspapers said the alleged event was held on the same day that Matt Hancock, then Health Secretary, urged people to “please stick with the rules”.

At the time the party is said to have taken place, people were only permitted to meet one other person from outside their household in an outdoor, public place, and were told to keep two metres apart.

According to the reports, sources claimed that roughly 20 staff attended, drinking alcohol and eating pizza.

Some were said to have gathered in offices inside No 10 and others in the garden. It is alleged that drinking went on late into the evening.

The PM reportedly told one attendee that they deserved a drink for “beating back” the virus.

The papers said that, when asked about Mr Johnson’s “beating back” comment and his presence at the alleged party where staff were said to be drinking and socialising, a No 10 spokesperson told them: “In the summer months Downing Street staff regularly use the garden for some meetings.

“On May 15 2020 the Prime Minister held a series of meetings throughout the afternoon, including briefly with the then-Health and Care Secretary and his team in the garden following a press conference.

“The Prime Minister went to his residence shortly after 7pm. A small number of staff required to be in work remained in the Downing Street garden for part of the afternoon and evening.”