Number 10 backed down on efforts to block the move triggered by opposition parties.
Boris Johnson will face a formal investigation over whether he misled parliament about partygate.
Opposition parties used Commons procedure to push for a probe after the prime minister refused to quit over his lockdown fine.
Mr Johnson has come under intense pressure to explain his insistence in parliament that all rules were followed in Downing Street.
He said this week he did not intentionally mislead the Commons, an offence usually considered a resignation issue, despite the Met confirming he attended a law-breaking party in June 2020.
Now the matter has been referred to a parliamentary standards watchdog after a Labour motion passed without a vote in the absence of any objections.
Number 10 backed down on efforts to kick the issue into the long grass with its own wrecking motion after failed attempts to rally Tory MPs last night.
Yet more bad news for the PM comes on the same day an influential senior Tory MP publicly turned on him.
Steve Baker – who was pivotal in unseating Theresa May – warned Mr Johnson that ‘the gig is up’ despite backing him on Tuesday.
In a shock speech, he said the contrition shown when the PM apologised to the Commons earlier this week ‘only lasted as long as it took to get out of the headmaster’s study’.
He added: ‘That’s not good enough for me, and that’s not good enough for my voters.’
Another Tory MP, Mark Harper, called on the PM to resign on Tuesday and defence select committee chair called told his colleagues: ‘It’s time to stop drinking the Kool-Aid.’
It’s unclear how many MPs have submitted letters of no confidence in Mr Johnson leadership but the failure to block the probe will increase speculation that the PM has lost significant support among his own party.
The new investigation will only begin after the Met has completed its own inquiry into alleged coronavirus law breaches at the heart of government.
Scotland Yard announced today any further fixed penalty notices for the prime minister or others in Downing Street will not be issued until after the local elections.
Mr Johnson is also yet to endure the full publication of the long-awaited Sue Gray report, which he has previously committed to releasing in full once the Met process is concluded.
The news that he will undergo another investigation over his conduct during lockdown comes after he told reporters joining him on his trip to India that he was committed to fighting the next general election as Tory leader.
Speaking before the result was confirmed, Cabinet Office minister Michael Ellis told the Commons the PM ‘has always been clear that he is happy to face whatever inquiries Parliament sees fit’.
Labour deputy leader Angela Rayner said MPs were having to resort to establishing a parliamentary investigation ‘because the prime minister has failed to do the decent thing and resign’.
The group, which is formally known as the Conservative Private Members' Committee, is the body which represents backbench Tory MPs. It acts as a forum for the rank and file to liaise with the government and plays a crucial role in organising Tory leadership elections.
The phrase ‘men in grey suits’, which refers to the Tory big hitters who hold sway in the party behind the scenes, has become synonymous with the committee. Its current chair is Sir Graham Brady.
Under 1922 Committee rules, Conservatives MPs can force a leadership election by submitting letters of no-confidence to the chair. A confidence vote is triggered if 15% of the parliamentary party submit the letters (that works out as 54 MPs). The letters are submitted anonymously and there is no public tally.
If the threshold is reached, a secret ballot of Tory parliamentarians will be held. Mr Johnson would need a simple majority of his own MPs to back him in order to hold on to his position.
Is he lost a confidence vote, the Tories would elect a new leader - and new prime minister - in a race which Mr Johnson would be barred from standing in. It’s unclear if he would remain PM during the election or whether an interim would take the reins while the process played out.
Get in touch with our news team by emailing us at webnews@metro.co.uk.
For more stories like this, check our news page.
