Mr Johnson has consistently rejected suggestions he broke Covid laws. His defence is believed to centre on the argument that he attended the gatherings in a work capacity.

Downing Street insiders said they have had minimal contact from the Metropolitan Police since it launched an investigation into claims of social gatherings during Covid lockdowns back in January.

Questions about Mr Johnson’s movements issued by the force have been handled by Mr Johnson’s private lawyers, rather than by Downing Street officials.

The full scale of how many people have been contacted by Scotland Yard remains unclear, given the Metropolitan Police does not publish regular updates or name those who are being investigated.

The scandal, which began to emerge in late 2021, was first investigated by Sue Gray, a senior civil servant.

Earlier this year, the investigation was handed over to the Metropolitan Police after it concluded there was enough evidence of potential rule-breaking in a dozen events.

Among the list of events being looked into are farewell parties for Downing Street advisers and civil servants, which took place in summer and winter of 2020, as well as in early 2021.