On Tuesday night, government sources outside Downing Street reacted with fury to the video, which they said had tarnished the reputations of ministers who were sent out to play down the controversy in the media. 

Senior Tory MPs also called for resignations in Number 10, with one singling out Dan Rosenfield, Mr Johnson’s chief of staff.

Several said ministers and officials across Whitehall had been forced to endure a backlash from industry leaders in their sector over Covid restrictions on the orders of Number 10. Others expressed anger that they had made personal sacrifices last December to comply with the rules while Downing Street staff had seemingly disregarded them.

“We’re f—–. How could they be so stupid?” one said.

A former minister said: “It’s a disaster, and some extreme humble pie needs to be eaten. I am absolutely furious because we’ve been trying to make the best of it on the basis of assurances, and this kind of thing just can’t happen.”

Senior Tory MP Charles Walker said on Tuesday night: “The No 10 party means that any future lockdowns will be advisory, whatever the law says”.

The leaked footage was shot in the media room at nine Downing Street, which was refurbished at a cost of £2.6 million in preparation for the proposed TV broadcasts.

One source told ITV News, which obtained the footage: “We all know someone who died from Covid, and after seeing this all in the papers I couldn’t not say anything. I’m so angry about it all, the way it is being denied.”

A Downing Street spokesman said: “There was no Christmas party. Covid rules have been followed at all times.”