The investigation into whether Boris Johnson deliberately misled parliament over the partygate scandal has begun with a call for evidence – and individuals will be allowed to contribute to the inquiry anonymously.

Labour veteran Harriet Harman, currently the longest-serving female MP, has been selected to chair the probe which will be conducted by the Commons Privileges Committee.

Ms Harman was unanimously elected to take up the role.

A statement from the committee said it is “calling for evidence submissions and accounts from those with knowledge of events related to the inquiry”.

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It continues: “Specifically, the committee is seeking witness information and evidence which would enable it to determine whether or not the Right Honourable Member for Uxbridge and South Ruislip misled the House.”

The committee said it will take a range of written and oral evidence.

It added that this can be submitted anonymously “subject to the chair being able to identify the individual’s identity in conjunction with committee staff, as well as the relevance and probity of their evidence”.

The inquiry will consider evidence related to:

• Mr Johnson’s knowledge of the activities in 10 Downing Street and the Cabinet Office under COVID regulations, from the occurrence of those events until now
• Any briefing given to, or inquiries made by, Mr Johnson relating to those events.

The deadline for submitting evidence is 29 July.

Oral evidence sessions are expected to begin in the autumn.

Members of the committee met for the first time on Wednesday morning.

Sir Ernest Ryder, a former Lord Justice of Appeal and Senior President of Tribunals, has also been appointed as an adviser.

Labour’s Harriet Harman unanimously elected to lead probe

The Privileges Committee will determine whether Mr Johnson is in contempt of Parliament for misleading MPs with his repeated denials of lockdown-busting parties in Downing Street.

Back in April, MPs backed a Labour-led motion calling for the privileges committee to examine allegations the prime minister misled the Commons when he denied lockdown rules were broken in Downing Street.

Tory MPs had earlier been ordered to back a government attempt to delay the vote until inquiries by the Met Police and civil servant Sue Gray had concluded.

But, in a late reversal shortly before the debate began, Commons Leader Mark Spencer said Tory MPs could vote however they wanted on Labour’s motion.

Subsequently, the motion was nodded through without a vote.

Labour say PM misled MPs

The motion tabled by Labour and the leaders of seven other opposition parties stated that the prime minister made at least four separate remarks in the Commons which “appear to amount to misleading the House”:

• On 1 December 2021, Mr Johnson told MPs “that all guidance was followed in No 10”.

• On 8 December 2021, the prime minister told the Commons: “I have been repeatedly assured since these allegations emerged that there was no party and that no COVID rules were broken.”

• Also on 8 December 2021, he said: “I am sickened myself and furious about that, but I repeat what I have said to him: I have been repeatedly assured that the rules were not broken.”

• Finally on the same date: “The guidance was followed and the rules were followed at all times.”

Now that the Metropolitan Police’s partygate probe has concluded, the parliamentary investigation can get underway.

PM made comments about partygate revelations ‘in good faith’

The PM has faced persistent calls to resign over partygate.

He survived a confidence vote earlier in June by 211 votes to 148 – but 40% of his own Conservative MPs decided to back the prime minister.

Defending Mr Johnson in the debate on the original motion in April, Cabinet Office Minister Michael Ellis said the prime minister did not mislead the Commons, but made comments about partygate revelations “in good faith”.

“He made clear that he did not think at that time, that the event was in contravention of COVID rules, however he has apologised for his mistake, paid his fine and accepted the findings of the Metropolitan Police,” Mr Ellis said.

“There is a difference between a deliberate and an inadvertent situation and I think most people would accept that.”

In May, senior civil servant Sue Gray published her long-awaited report into the partygate scandal.

Details of drunkenness, fighting and late night parties at the heart of government were laid bare in the damning report and Ms Gray said “senior leadership” must bear responsibility.

The report, which also detailed karaoke, wine spillages, aides being sick and others being rude to security staff and cleaners, revealed behaviour in Downing Street during 2020 and 2021 when COVID-19 restrictions were in place across the country.

Its publication came after the Met Police concluded their investigation into lockdown-breaking events in Downing Street and Whitehall, which resulted in 126 fines being issued for 83 people.

Mr Johnson has already apologised after receiving one fine for attending a gathering to mark his birthday in June 2020 – and questions have been raised about why he did not receive penalties relating to other occasions.