Commons Speaker Sir Lindsay Hoyle confirmed that, following legal advice, the committee‘s findings would fall within the remit of the Recall of MPs Act if Mr Johnson was suspended for 10 days or more.
It would mean a petition to recall Mr Johnson would be opened for six weeks in his Uxbridge and South Ruislip constituency.
If 10 per cent of the electorate sign it then he would face a by-election.
The Privileges Committee on Thursday confirmed that its inquiry will go ahead despite Mr Johnson’s resignation as Conservative leader and his expected departure from Number 10 at the beginning of September.
The committee said “some have suggested” the inquiry is no longer necessary.
It added: “Our inquiry, however, is into the question of whether the House was misled, and political developments are of no relevance to that.
“The House charged the committee with this task and we are obliged to continue with it.”
The Met issued 126 Partygate fines after a number of lockdown busting gatherings in Downing Street and across Whitehall.
Police issued Mr Johnson with a £50 fixed-penalty notice for being at his surprise birthday party in the Cabinet Room in June 2020.
However, the prime minister had previously insisted that no lockdown rules were broken in Downing Street.
On December 1, 2021, Mr Johnson told MPs in the Commons: “All guidance was followed completely in Number 10.”