Keir Starmer and Angela Raynor receive questionnaires from the police

The revelation came after Dominic Cummings said blockers were holding parties in Checkers and Carrie Johnson was accused of arguing with a staff member who later left.

Mr Cummings, Boris Johnson’s former chief adviser, said both Sue Gray and the metropolitan police had failed to investigate allegations that the meetings had taken place in the prime minister’s country house.

In an interview with the Unherd website on Tuesday, he criticized Ms. Johnson in detail and suggested that she hosted the No. 10 party, which was attended by journalists from Westminster.

“Carrie is friends with many of them and it has been said that they hang out with her and him,” he said. “But apparently the police and Sue Gray have decided not to investigate this – or to investigate the Checkers as well.”

Asked if parties had taken place in the majestic home, he replied: “That’s what people say.”

A source on Downing Street at the time of the pandemic told The Telegraph that there was “general chatter and concern” from officials and special advisers at Mr Johnson’s personal office that the rules were being violated at Checkers, adding: “I know there have been gatherings.”

A second source said there were “rumors” of a rule violation at property number 10 during the pandemic.

On Tuesday night, Downing Street did not directly deny that the events had taken place, but pointed to the fact that Mr Cummings had been encouraged to pass on any evidence of evidence to both Gray and Met, who are investigating the trail.

Ms Gray said she would not reopen her investigation if other events came to light, but acknowledged that “events that were not the subject of an investigation may have occurred”.

She is already facing criticism for her decision not to consider allegations that a party was held in Mr and Mrs Johnson’s private apartment in November 2020, in breach of blocking rules.

In a report released last week, she said she had not further investigated the event after the Metropolitan Police launched a formal investigation, and that while she was “considering whether to further investigate the event or not”, she was “Concluded that it was not appropriate or proportionate to do so.”