Explainer-How will the 'partygate' inquiry into Boris Johnson work?

LONDON (Reuters) - Former British prime minister Boris Johnson will be grilled by lawmakers on Wednesday as they decide whether he intentionally misled parliament about illegal parties at his office during coronavirus lockdowns.

Below is a look at how parliament's privileges committee is conducting its inquiry and how it could affect Johnson, who remains an influential figure in British politics and attempted a return to the premiership as recently as October.

WHAT IS THE PRIVILEGES COMMITTEE?

It is one of the many committees of lawmakers in the British parliament which oversees the government's work and parliament's internal affairs.

The Committee of Privileges examines specific matters referred to it by parliament that involve a potential contempt of parliament and breaches of parliamentary privilege by lawmakers.

Lawmakers, including from Johnson's Conservative Party, backed an opposition motion last April that his statements "appear to amount to misleading the House" and should be investigated by its Committee of Privileges.

Johnson has since resigned as prime minister but remains a lawmaker representing a west London constituency.

WHO IS PART OF THE COMMITTEE?

The seven-member committee is made up of four Conservatives and three opposition lawmakers, in proportion to the parties' representation in parliament. The committee, by convention, is chaired by an opposition lawmaker and Labour's Harriet Harman is its current chair.

HOW WILL THE COMMITTEE CARRY OUT ITS WORK?

The committee has been collecting "written evidence" - diaries, emails, photos, documents and mobile phone messages - from Johnson and his No. 10 Downing Street staff.

On March 3, the committee said the evidence "strongly suggests that breaches of guidance would have been obvious" to Johnson at the time he was at the gatherings.

On Tuesday, it published a document given to it by Johnson in which he said there was no evidence he intentionally misled lawmakers.

In its oral evidence stage of the inquiry, the committee will call a range of individuals - including Johnson on Wednesday - to testify under oath in televised hearings.

All oral evidence will be taken publicly but the committee has said it will consider requests to give evidence anonymously or in private on a case-by-case basis if necessary.

Johnson, or any other witness, may be accompanied by a legal adviser from whom they can take advice during the session.

WHAT POWER DOES THE COMMITTEE HAVE?

The committee only has the power to issue a report to parliament setting out its findings from the inquiry and whether it believes Johnson "committed a contempt". It can also recommend what, if any, sanction he should face.

Possible sanctions include reprimanding Johnson, requiring him to make an oral or written apology, suspending him for a number of days or even expelling him.

A suspension of 10 or more sitting days would automatically lead to a recall petition, which if signed by more than 10% of the electorate in his constituency, would trigger a fresh vote for his parliamentary seat.

Members of parliament will vote on whether to ratify the committee's report and approve any sanction.

WHAT IF THE COMMITTEE FINDS JOHNSON MISLED PARLIAMENT?

A ruling that Johnson misled parliament intentionally, whatever the sanction, would make it harder for him to convince his party — and the British public — that he could ever become prime minister again.

While expulsion from parliament would mean he would be unlikely to ever return to high office, there is no rule preventing him running for election to parliament again.

CAN JOHNSON CHALLENGE THE FINDINGS?

Not exactly. If the committee intends to criticise Johnson, it will first send him a warning letter with the evidence it has used to arrive at its findings.

Johnson can respond to any such letter within 14 days, and the committee will consider the response before reporting its findings to the house.

WHAT HAPPENS IF THE COMMITTEE FINDS IN FAVOUR OF JOHNSON?

If the committee concludes that Johnson did not mislead parliament, he could use the findings to strengthen his case for a political comeback.

(Reporting by Sachin Ravikumar; Editing by Christina Fincher and Gareth Jones)