While he apologised for the incident and implored MPs to concentrate on issues such as the war in Ukraine and cost of living, MPs will return to the Partygate topic with a vote on Thursday morning.
MPs will vote on whether Mr Johnson should be referred to the Committee of Privileges for investigation into whether he lied to MPs about his knowledge of the rule-breaking in Downing Street and Whitehall.
But did he lie to Parliament? And what could happen next to the Prime Minister?
Did Boris Johnson lie to Parliament about Partygate gatherings?
Mr Johnson has been accused of lying to Parliament about his previous knowledge of rule-breaking at gatherings held in Downing Street and Whitehall while Covid restistictions prohibited such gatherings.
Speaking to the House of Common in December 2021, the Prime Minister told MPs that “the guidance was followed and the rules were followed at all times” during alleged gathering held in Downing Street and Whitehall.
Opposition MPs have accused Mr Johnson of deliberately misleading Parliament with this statement, after he himself was found by the Met Police to have broken rules and was issued a £50 fixed penalty notice.
However, the Prime Minister has repeatedly insisted that he has not knowingly lied to MPs about the issue.
When asked directly by Conservative MP Peter Bone if he had “deliberately” mislead Parliament, he replied bluntly: “No.”
At this point, Mr Johnson has not been found to have misled Parlaiment.
What does the ministerial code say about lying to Parliament?
As set out in the ministerial code, any ministers who “knowingly mislead Parliament will be expected to offer their resignation to the Prime Minister”.
Mr Johnson has reiterated that “it did not occur to me” that the gathering on 19 June 2020 broke rules, meaning that it may be difficult to prove whether he “knowingly” lied to the house.
He had added that he was “repeatedly assured” that any such gathering which had been held in Downing Street or Whitehall had been within the Covid rules at the time.
Speaker of the House Sir Lindsay Hoyle has made clear that he cannot police the ministerial code.
Instead, Lord Geidt, the Prime Minister’s adviser, will investigate such issues when they are referred to him by the Prime Minister.
Labour have now asked for a vote to be brought to the house during a debate on 21 April 2021 in which MPs will choose whether to refer the incident to the Committee of Priviliges, which investigates incudent in which there has been an alleged contempt of Parliament.
Will MPs vote to have Boris Johnson investigated for lying to Parliament?
While Labour have tabled the vote to refer Mr Johnson, there is no guarrantee that it will go through.
The Conservative party currently holds a majority of 75 in the House of Commons, meaning that there will need to be a major revolt within the backbenches for the vote to pass.
Although most Tory MPs, both in ministerial positions and on the backbenches, have pledged their support for the Prime Minister, some have come out against Mr Johnson.
Former chief whip Mark Harper has revealed that he has lodged a letter of no-confidence to the 1922 committee, after telling him that he “no longer thinks he is worthy of the great office that he holds.”
A Labour source is also quoted as saying: “Any Conservative MP considering voting to block this investigation would be voting for a cover-up.”
What happens next if MPs vote to investigate Boris Johnson?
In the unlikely event that the vote passes through the House of Commons on 21 April, Mr Johnson will be referred to the Committee of Privileges where an investigation into his statement will take place.
The committee will be able to summon reports - such as Sue Gray’s full inquiry report into the gatherings - as well as photographic evidence and other related documents.
If he is found to have lied after this investigation by the committee, he would be expected to resign from his position in line with with ministerial code.