Johnson, who won a landslide victory in a 2019 election, has faced a barrage of criticism over alleged parties in government offices, including his own, in breach of COVID-19 lockdowns.

Around 40 staff gathered in the garden for the drinks party, including Johnson and his wife Carrie Johnson, ITV said, even though at the time social mixing between households was limited to two people outdoors.

An email was sent by the Prime Minister’s Principal Private Secretary Martin Reynolds to over 100 employees in Downing Street on May 20, 2020, ITV said. The leaked email asked them to bring alcohol to the party and to “make the most of the lovely weather”.

“After what has been an incredibly busy period it would be nice to make the most of the lovely weather and have some socially distanced drinks in the No10 garden this evening,” Reynolds said in the email. “Please join us from 6pm and bring your own booze!”

Johnson’s office declined to comment.

At the time, schools were shut, and pubs and restaurants were closed, with strict controls on social mixing. Two people from different households were allowed to meet outdoors but only if maintained a distance of 2 metres.

A senior government official Sue Gray is currently investigating the allegations of at least five parties held in government departments last year during lockdown restrictions.

The allegations have dismayed voters who were told by the government to carefully stick to social distancing rules.

Johnson’s Conservatives lost an election in a previous stronghold last month, stepping up pressure from his own lawmakers to reform his team of advisers.

Britain’s official death toll from the COVID-19 pandemic rose above 150,000 on Saturday, the second highest in absolute terms in Europe, behind only Russia’s.

(Reporting by Andrew MacAskill; Editing by Alison Williams)