Johnson says disciplinary action will be taken if it was found that rules were broken after a video surfaced showing his staff laughing over how to explain a gathering in Downing Street during a Covid-19 lockdown last Christmas.

Boris Johnson says he had been
Boris Johnson says he had been "repeatedly assured" that there was no party inside his number 10 Downing Street office and that no rules were broken since the allegations first emerged. (Reuters)

British Prime Minister Boris Johnson has apologised and announced an internal probe into allegations of a Christmas party at Downing Street last year when social gatherings were banned under Covid-19 rules.

"I apologise unreservedly for the offence that it has caused up and down the country and I apologise for the impression that it gives," he told parliament on Wednesday.

It came after a leaked video showed his staff laughing and joking about a party in Downing Street during a lockdown.

Johnson said he was furious but had been repeatedly assured there had not been a party. However, disciplinary action would be taken if it was found that rules were broken.

Allegra Stratton, who was his press secretary at the time the video was recorded in December 2020, quit shortly after his remarks, the political editor of the Times reported.

"I will regret those remarks for the rest of my days and offer my profound apologies to all of you for them," Stratton was quoted by the Times as saying in a statement.

READ MORE: UK PM opposed Covid lockdown as only ‘over 80’ were dying – former aide 

'Taken for fools'

The footage appears to contradict more than a week of denials by Johnson and his ministers that a party took place.

The Mirror newspaper reported in 2020 that there had been several parties including a wine-fuelled gathering of 40 to 50 people to mark Christmas.

The video aired by ITV, shows Stratton fielding questions from advisor Ed Oldfied and other staff during a rehearsal press conference on December 22.

The group laughs and trade jokes as they discuss a "fictional party" four days earlier, which reportedly involved food, drink, games and "secret Santa" gift-giving.

"This fictional party was a business meeting and it was not socially distanced," she laughs over joking exchanges about "cheese and wine" and whether the prime minister would "condone" such an event.

At the time of the Downing Street gathering, tens of millions of people across Britain were banned from meeting close family and friends — or even from bidding farewell to dying relatives.

Opposition Labour Party leader Keir Starmer accused Johnson of "taking the public for fools", while Ian Blackford of the Scottish National Party called for Johnson to resign.

READ MORE: Boris Johnson on hot seat as watchdog investigates Downing Street refurb

Source: TRTWorld and agencies