Boris Johnson has refused to say whether he will resign if he is fined for breaching lockdown restrictions.
The Prime Minister is expected to be among the more than 50 individuals who will receive legal questionnaires from Metropolitan Police officers investigating gatherings in No 10 and Whitehall.
Scotland Yard said it will be dispatching the questionnaires by the end of the week as officers working on Operation Hillman consider whether to widen the investigation to cover a Christmas quiz in No 10 in December 2020.