The Privileges Committee has been conducting an inquiry into whether he misled MPs with his assurances over lockdown-busting parties in Downing Street.
Mr Johnson, who assured MPs while he was prime minister that “all guidance was followed completely in No 10”, could face suspension from the House of Commons or even a by-election if the committee finds him in contempt of Parliament.
If the Committee decides to criticise Mr Johnson, it will not come to a final conclusion until it has taken into account any further submissions from Mr Johnson
The Times reported that the panel of MPs has sent Mr Johnson a draft of the report which will determine his political future.
He has two weeks to respond to the committee before it delivers its verdict to the Commons, which will then vote on whether to approve whatever sanction it recommends, according to the newspaper.
A spokesperson for the panel said: “The Committee is proceeding in accordance with its previously published procedure. Under that procedure, if the Committee decides to criticise Mr Johnson, it will not come to a final conclusion until it has taken into account any further submissions from Mr Johnson.
“The Committee will then report to the House in the usual way, and it will be for the House – not the Committee – to decide on this matter.”
The panel of MPs, chaired by Labour’s Harriet Harman but which has a Tory majority, can make a recommendation on any punishment but the ultimate decision will lie with the full House of Commons.
Sanctions could range from a simple apology to ordering that Mr Johnson be suspended from Parliament.
Any suspension of 10 sitting days or more could trigger a recall by-election in his Uxbridge and South Ruislip seat, putting his parliamentary career in jeopardy.
The panel’s deliberations have been slightly delayed after it was last month passed concerns from Cabinet Office officials that Mr Johnson may have also breached coronavirus lockdown rules with events in Chequers and Downing Street.
Entries in the former prime minister’s official diary, which came to light during a review by taxpayer-funded lawyers ahead of the Covid public inquiry, reportedly revealed visits by friends to Chequers during the pandemic and new allegations about his behaviour in Downing Street.
Mr Johnson, who believes he is the victim of a stitch-up, endured more than three hours of questioning by the Privileges Committee in March.