Fiona Onasanya, the MP facing a recall petition after lying about a speeding ticket, is expected to learn by Thursday morning whether her electorate has kicked her out of parliament.

Ten “signing places” across her seat of Peterborough in Cambridgeshire will close at 5pm on Wednesday and a count of signatures on the petition will begin immediately. If it has attracted the support of 10% of eligible voters – 6,967 people – the former Labour whip will be forced out of office and a byelection will be called.

A byelection would make history as the first under new laws that give voters the chance to recall their MP. If one does take place, then Nigel Farage’s Brexit party is expected to stand its first parliamentary candidate, but a spokesman said no decision had yet been made on whether Farage might stand himself. Peterborough voted 60-40 to leave in the 2016 EU referendum.

Council officials hope an announcement on the petition will be made on Wednesday night, but this can only happen once constituents’ signatures have been counted and the Speaker, John Bercow, has been informed of the result.

Bercow is expected to be in the House of Commons until around 8pm, when an Opposition day debate is expected to end. If the count goes beyond the end of the debate, a result may be released on Thursday or Friday.

Any byelection would have to be held between 21 and 27 working days of it being triggered, meaning it would most likely take place two or three weeks after the anticipated European elections on 23 May.

Labour, as Onasanya’s former party, would trigger the process by moving a motion in parliament. Onasanya, 35, could in theory stand in a byelection, but friends have told the Guardian this is unlikely.

A Brexit candidate could well take votes off both main parties but would be particularly challenging for the Conservative candidate Paul Bristow. Labour has chosen Lisa Forbes, a Unite activist, to stand and has been vigorously campaigning in the city.

Labour won Peterborough by just 607 votes in the 2017 general election, beating Conservative Stewart Jackson, who had held the seat since 2005.

The petition, which is expected to cost the government about £500,000, was automatically triggered after Onasanya failed to overturn a conviction for perverting the course of justice.

No MP has yet been recalled under the statute. An attempt to recall the DUP MP Ian Paisley Jr in September failed when 9.4% of constituents supported it.

Onasanya, a solicitor, spent a month in prison and wore an electronic tag in parliament after she was jailed for lying to avoid a speeding charge. In March, after the petition was announced, she appealed to constituents to return her to parliament in a recorded statement released on social media.



