BORIS Johnson has been told he “must come clean” and admit if we attended a “Covid rule-breaking party” after a leaked email revealed Downing Street staff were invited to lockdown drinks when the UK was locked down.

According to ITV, staff were asked to “bring your own booze” on May 20 2020, five days after another event where the Prime Minister and his wife Carrie Johnson were pictured with Downing Street officials having wine and cheese in the garden.

A leaked email was sent by the Prime Minister's Principal Private Secretary Martin Reynolds to more than 100 Number 10 employees, including Mr Johnson's advisors, speechwriters and door staff.

In the email, Mr Reynolds reportedly told staff “it would be nice to make the most of the lovely weather and have some socially distanced drinks in the No10 garden this evening”.

He added: "Please join us from 6pm and bring your own booze!"

ITV News reported that around 40 staff gathered in the garden that evening, eating picnic food and drinking and allegedly included the Prime Minister and his wife Carrie Johnson.

Ian Blackford, the SNP leader in the House of Commons, said: “Boris Johnson must come clean and admit whether he attended, or was aware of, this Covid rule-breaking party in his own back garden.”

The MP for Ross, Skye and Lochaber added: “People will find it utterly outrageous that while the rest of us were banned from public gatherings, the most powerful people in the Tory Government were boozing up at No 10 Downing Street, proving yet again that it’s one rule for them and another for the rest of us.

“Boris Johnson’s Tory Government is the most corrupt in decades. If the Prime Minister had a shred of integrity or an ounce of shame, he would have resigned many months ago. He has no moral authority left, and as he won’t go his Tory MPs have a duty to remove him from power."

Deputy Labour leader Angela Rayner said: “Boris Johnson has consistently shown that he has no regard for the rules he puts in place for the rest of us. He is trying to get officials to take the fall for his own mistakes, but he sets the tone for the way Downing Street and the rest of Government operates.

“At the time this party took place, key workers on the frontline were working round the clock to keep us all safe, people suffered loneliness and loss in unimaginably tough circumstances and for the majority of the country our freedom was limited to a daily walk.

“Labour has welcomed Sue Gray’s inquiry, but we need confirmation that this latest revelation, and any other parties not yet revealed by press investigations, will be covered by her probe.”

Liberal Democrat leader Sir Ed Davey said the event was a “kick in the teeth for everyone who has sacrificed so much during the pandemic”.

He said: “This is yet more evidence that while the vast majority of people were sticking to the rules, those in No 10 were breaking them.

“It is a kick in the teeth for everyone who has sacrificed so much during the pandemic, from those who weren’t able to visit loved ones in hospital to nurses left wearing binbags as PPE.

“To add insult to injury, on the very same day that the Culture Secretary said people could only meet in pairs outdoors, it seems Boris Johnson’s staff were holding a boozy party in Downing Street.

Asked during a visit to a vaccination centre in west London if he had attended the May 20 event, the Prime Minister said: "All that, as you know, is the subject of a proper investigation by Sue Gray."