Scotland’s First Minister has urged Boris Johnson to “come clean” over an alleged party at Downing Street after a video surfaced appearing to show aides joking about it.

The footage, obtained by ITV News, shows the Prime Minister’s then press secretary Allegra Stratton practicing for a press briefing by fielding questions from other Number 10 staff – one of whom asks about a “fictional” gathering in Downing Street, about which Ms Stratton appears to joke.

Speaking to the BBC on Wednesday, Nicola Sturgeon said the Prime Minister “appears to be not being straight and truthful about it”.

Mr Johnson has come under pressure in the past week over the allegations of a gathering – which he has previously denied took place, although the Cabinet Secretary has been instructed to investigate.

“The Prime Minister appears to be not being straight and truthful about it,” Nicola Sturgeon told the BBC.

“That really matters because he is likely to be asking people to do difficult things again over this Christmas and it’s really important that he’s straight and honest with people – if mistakes were made, to own them, to apologise for them.

“I think this is a really serious issue for the Prime Minister and I think he has to come clean.”

Ms Sturgeon went on to say that at the time the alleged party took place, a new strict lockdown was a little more than a week away.

“This was last Christmas – 18 and 19 December are dates engraved on my mind as perhaps one of, if not the lowest, darkest point in the whole pandemic.

“We had told people they could have some very limited normality over Christmas then at the last minute we had to snatch that away and dash people’s hopes.

“That is what makes people so angry about what was allegedly happening in Downing Street.”

Boris Johnson in the House of Commons
The Prime Minister has asked the Cabinet Secretary to investigate (House of Commons/PA)

The First Minister also pointed to her own mistakes around the same time, when she was pictured speaking to people at a funeral without her mask on, for which she apologised.

“It’s really important that we have trust in public messaging and trust in people making decisions,” she said.

Ms Sturgeon’s comments come after her deputy described the video of Ms Stratton as “one of the most appalling things” he has seen in his political career.

Speaking to BBC Radio Scotland’s Good Morning Scotland programme, John Swinney said: “That video last night is just one of the most appalling things I have seen in my political life.

“I think it shows contempt at the heart of Downing Street for members of the public, and that is exactly what you do not need at a time of national emergency and of the gravity that we face.”

He went on to say he is concerned the video will impact on compliance with coronavirus restrictions in the future.