A Whitehall investigation into potentially lockdown-breaking Christmas parties could examine Boris Johnson’s participation in a festive quiz, the Health Secretary has said.

The Prime Minister is facing calls to respond to claims that he broke coronavirus rules, with Labour claiming he might have misled Parliament.

Sajid Javid said it would be up to Cabinet Secretary Simon Case to decide whether to include the quiz in his inquiry into parties reportedly held in the winter of 2020.

The head of the Civil Service is already probing claims of a December Christmas party and November staff leaving do at No 10, as well as festive drinks at the Department for Education.

Government gatherings
Cabinet Secretary Simon Case is looking into allegations that lockdown rules were breached (Aaron Chown/PA)

Downing Street said Mr Johnson “briefly” attended the “virtual” quiz, reported to have been held on December 15 last year.

An image published by the Sunday Mirror shows the Prime Minister flanked by colleagues, one draped in tinsel and another wearing a Santa hat, in the No 10 library.

The newspaper quoted a source who claimed that many staff were huddled by computers in their Downing Street offices, conferring on questions and drinking alcohol while the quiz was taking place.

Tier 2 restrictions that London was under on December 15 stated that there could be no mixing of households indoors, apart from support bubbles, and a maximum of six people outside.

Coronavirus – Sun Dec 12, 2021
Prime Minister Boris Johnson is facing calls to respond to claims that he broke coronavirus rules (Kirsty O’Connor/PA)

Mr Javid told Sky News: “I saw the photo of that quiz, like anyone else. What I can see is it’s a virtual quiz with the Prime Minister sitting at his desk.”

He added: “I don’t know all the details. What I can see (is) it’s a virtual quiz.

“And Simon Case has been given a broad remit to investigate anything that he thinks… any type of gathering in Downing Street that should be looked at on any particular day he wants to.

“And so if he wants to look at this he will – that’s going to be a decision for him.

“It’s not right, I think, for a minister to tell him what he should or should not investigate.”

Labour said the Prime Minister “might have misled” MPs after he told the Commons he had been given assurances that social distancing regulations were not broken by No 10 last year.

Sir Keir Starmer said it is “very hard” to see how the Tier 2 rules could have been adhered to in the quiz.

Official guidance set out that there should be no work lunches or parties “where that is a primarily social activity” and they were not exempted for “work purposes”.

Shadow foreign secretary David Lammy said the Prime Minister’s credibility is “in tatters”.

Asked on BBC Breakfast why Sir Keir stopped short of calling for Mr Johnson to resign, instead saying he is “unfit to lead”, Mr Lammy said: “Well, that must, in the end, be a matter for the Prime Minister.”