BORIS Johnson is facing calls to quit after a leaked video showed his aides joking about a Christmas party at Downing Street during lockdown despite multiple denials.

The Prime Minister’s then Press Secretary Allegra Stratton is seen laughing when asked by a colleague about the alleged event during a mock press conference.

In the tape made on December 22 last year, adviser Ed Oldfield asked Ms Stratton to explain reports on Twitter about “a Downing Street Christmas part last Friday night”.

The date matches the disputed party  reported to have happened on December 18, despite London going into Tier 3 Covid restrictions two days before. 

In the video, which was leaked to ITV, Ms Stratton replied “I went home” before appearing to consider what the correct answer should be.

During the rehearsal, filmed as part of a subsequently-abandoned plan for Ms Stratton to lead televised press briefings, Mr Oldfield pressed her for an answer.

“Would the Prime Minister condone having a Christmas party?” he asked.

Ms Stratton asked “What’s the answer?” and staff in the press room appeared to suggest ideas, with one saying “it wasn’t a party, it was cheese and wine”.

Ms Stratton replied: “Is cheese and wine all right? It was a business meeting.”

She then noted “this is recorded”, adding: “This fictional party was a business meeting … and it was not socially distanced.”

The leaked footage was shot in the media room at 9 Downing Street, which was refurbished at a cost of £2.6m in preparation for the televised broadcasts before the plan was ditched.

In response to ITV’s report, a Downing Street spokesman said: “There was no Christmas party. Covid rules have been followed at all times.”

Earlier, Mr Johnson refused to deny a Christmas party took place after a newspaper report that staff were asked to bring “Secret Santa” gifts.

The Prime Minister’s official spokesman insisted point blank on Monday that “there was not a party” at No 10 on December 18 last year.

However, after the Times reported the event was organised by staff over WhatsApp several days in advance, Mr Johnson refused to repeat his own spokesman’s claim. 

Instead, he claimed no rules were broken, despite London being under Tier 3 rules, meaning a ban on social mixing indoors and office parties.

On a visit to a prison in London intended to show he was tough on crime, Mr Johnson was asked about the potential lawbreaking under his own roof.

He said: “What I can tell you is that all the guidelines were observed, continue to be observed.

Asked if he investigated personally, he said: “I am satisfied myself that the guidelines were followed at all times.”

SNP Westminster leader Ian Blackford said of the leak to ITV: "This video is damning and leaves the Prime Minister with a lot to answer for.

"When every individual up and down the country was told to stay at home in order to protect the NHS, the Tories were instead having a Christmas party which, as a senior staff member has now confirmed, was "not socially distanced..

"If this is true, then the Prime Minister's position is untenable and he must remove himself from office immediately.”

Labour leader Sir Keir Starmer said Mr Johnson must "come clean and apologise”.

He said: “People across the country followed the rules even when that meant being separated from their families, locked down and – tragically for many – unable to say goodbye to their loved ones.

“They had a right to expect that the Government was doing the same.

“To lie and to laugh about those lies is shameful.

“The Prime Minister now needs to come clean and apologise.

“It cannot be one rule for the Conservatives and another for everyone else.

“The Government broke the rules, they partied and now they are laughing about it.

“Unfortunately, we have a Prime Minister who is socially distanced from the truth.

“Instead of accepting that and being honest about it, the Prime Minister is pretending there weren’t breaches of any of the rules.

He added: “You don’t need a great long criminal investigation to get to the bottom of this - it is pretty obvious what happened.”

Ministers are yet to explain how the alleged bash complied with the rules in place at the time, despite coming under pressure since an initial report in the Daily Mirror last week.

The newspaper said two events took place in No 10 in the run-up to the festive season last year, including Mr Johnson giving a speech at a leaving in November’s lockdown.

The other was said to be a staff party in December where party games were played, food and drinks were served, and festivities went on past midnight.

At the time, the Tier 3 rules explicitly banned work Christmas lunches and parties where it is “a primarily social activity and is not otherwise permitted”.

Two Labour MPs have asked the Metropolitan Police to investigate.

Families who lost loved ones during the pandemic have also said they are "sickened" by the thought of a No 10 Christmas party during restrictions that they followed.

The Times reported that around 30 people initially attended the December party, some wearing Christmas jumpers, while others later joined in an “impromptu” fashion.

The paper said staff brought food and alcohol, rather than taxpayers paying for it.

It quoted a source saying: “Of course it was premeditated because everyone came with Secret Santa presents. It was arranged at least a week in advance via WhatsApp with a follow-up email.”

The source added that there was a “proper spread” of food that people had brought along with alcohol.

“The majority of people there were civil servants with a few special advisers and others there. But it was mostly officials.”