UK's Johnson cannot answer party questions because of police, minister says

British Prime Minister Boris Johnson cannot answer specific questions over lockdown parties at his Downing Street office and residence because he does not want to prejudice a police investigation into 12 gatherings, his deputy said on Tuesday.

British police are reviewing more than 500 pieces of paper and over 300 photographs as part of an investigation into whether the Downing Street gatherings, including some attended by Johnson himself, broke Covid-19 lockdown laws. The inquiry is expected to take weeks.

"If he does start answering specific questions that have been referred to the police, he will be accused, in fact fairly and rightly, of prejudicing or preventing or interfering in that investigation," Deputy Prime Minister Dominic Raab told Sky News.

Johnson's personal ratings and support for his Conservative Party have plummeted since revelations about parties emerged late last year, posing a serious threat to his premiership.

A limited report by senior civil servant Sue Gray on Monday found that alcohol-fuelled events had taken place at Downing Street when lockdown rules were in force. Gray said there had been "serious failures of leadership" and that some of the events should not have been permitted.

Opinion polls showed British voters felt Johnson should resign: 69% in a Savanta ComRes poll and 63% in a YouGov survey.

Opposition Labour Party leader Keir Starmer said on Monday Johnson was unfit to lead the country and should quit, while Conservative former Prime Minister Theresa May asked if Johnson had simply ignored the Covid rules or didn't understand them.

Although there is rising dissent in his own party, in order to trigger a leadership challenge 54 of the 359 Conservative members of parliament (MPs) must submit letters of no confidence and that figure has not been reached.

After initially saying that no rules were broken, Johnson has repeatedly declined to answer specifics about his own attendance at some of the gatherings.

He later admitted being at one but said he thought it was a work event. On Monday, he repeatedly declined to say if he had been at a gathering at his own apartment above the 10 Downing Street office, citing the police investigation.

Opposition parties have said the police inquiry should not preclude Johnson from answering specific questions, especially in parliament.

"What happened was the Metropolitan Police asked that the full report not be published at the moment, but the idea that that prevents the prime minister from saying whether he was at a party on a particular day is absolute nonsense," Starmer told BBC TV.

Johnson has committed to publishing any further update from Gray, who said she had been unable to provide a "meaningful report" because of the police investigation, meaning further damaging revelations could still come.