Journalist Ros Atkins shared the clip on Twitter, in which he outlined what measures were in place in the days leading up to the alleged event and how people have reacted since the news has come to light.
He said: “In December last year, Covid cases were rising, restrictions were being tightened and Christmas plans were being changed.”
He then showed a clip from 16 December 2020 in which Johnson urged people to exercise “personal responsibility” as London went into tier three restrictions, meaning indoor gatherings including Christmas parties were banned.
He aired advice from experts at the time, the huge death rate, and reminded viewers that Johnson had urged people to “minimise contact with people from outside your household”.
“Hours after... there was a Christmas party in Number 10” he said.
“We don’t have anything explaining how this party could be within the rules because as BBC Reality Check notes ‘any party at Downing Street would have breached the government’s guidelines at the time’”.
Then, reminding viewers that Johnson banned Christmas gatherings on 19 December, Atkins said:
“Millions of Christmas gatherings had to be cancelled less than 24 hours after Downing Street had had a gathering of its own. And while the prime minister maintains this didn’t break the rules, he’s offered no evidence to explain why.
You can watch the video in full here:
The story of the No. 10 Christmas Party last December. In 4 mins. Produced Michael Cox. https://t.co/jig7Bro5sd https://t.co/nUHQaOk9Zd
His explainer comes after the Mirror reported that Downing Street staff held a Christmas party last year, flouting their own rules while the rest of the country was in lockdown.
Since the original story was published, other publications have appeared to corroborate the claims by citing further anonymous sources who allege multiple leaving parties were held throughout November and December last year.