Yet his intervention proved an outlier as most Tory MPs who spoke in the debate gave support to Mr Johnson, many citing the Ukraine war as the reason he should remain in place.
On Wednesday, Labour will table a motion calling for the Committee of Privileges to be tasked with investigating whether the Prime Minister misled Parliament over ‘partygate’ claims.
Mr Johnson initially insisted all Covid guidance was followed when allegations first surfaced late last year of parties in Downing Street that broke lockdown rules.
Yet 50 Fixed Penalty Notices have now been issued by the Metropolitan Police over Covid law-breaking in Government buildings, with the investigation still ongoing.
Mr Johnson, Rishi Sunak, the Chancellor, and Carrie Johnson, the Prime Minister’s wife, were all fined for a gathering to mark Mr Johnson’s birthday on June 19, 2020.
A committee inquiry into whether Mr Johnson misled Parliament would carry political jeopardy, given that offence is traditionally considered a resigning matter for government ministers.
Yet the Prime Minister’s decision to push ahead with his trip to Gujarat and New Delhi reflects confidence from his inner circle that not enough Tory MPs will vote for the motion for it to pass.
A senior Government source rejected speculation the trip could be cancelled at the last minute because of the vote, saying it was “critical for jobs, trade, investment and diplomacy”.
Tory MPs will be whipped to oppose the motion in Thursday’s vote, with Conservatives expected to be warned off voting against the interests of their party leader.
Yet Labour is arguing that Tory MPs who oppose the motion are overseeing a “cover-up”, with preparations to use such decisions as political ammunition in their campaign for the local elections on May 5.
A Labour source said: “Any Conservative MP considering voting to block this investigation would be voting for a cover-up. They should reflect on the mess they got themselves into over Owen Paterson before falling into line.”
If the motion is passed and the committee is tasked with an investigation, it is possible documents and photographs could be requested from Sue Gray, the senior civil servant who oversaw an initial Whitehall investigation into ‘partygate’.
The Met has said they have been passed more than 300 photos relevant to their inquiries.
Mr Johnson was forced to back down last year after a backlash for whipping Tory MPs to delay a decision on suspending Mr Paterson, then a Tory MP, over lobbying claims.
The Prime Minister later admitted he had “crashed the car” over the way he handled the vote. Mr Paterson resigned as an MP and the Tories lost the subsequent by-election for his seat.
There is little public sign that enough Conservatives will rebel to pass the motion and trigger an investigation from the committee, though uncertainty remains.