How the drama has unfolded

SATURDAY, SEPTEMBER 26

Ferrier experiences “mild symptoms” of Covid-19 during the afternoon and takes a test. Since then, she has not said where she was when she fell ill or if she initially began isolating. Social media posts show she went to shops, a gym and a hair salon that day.

SUNDAY, SEPTEMBER 27

She attends a local church service and performs a reading in front of a mostly elderly congregation.

MONDAY, SEPTEMBER 28

In the morning, Ferrier says she is “feeling much better” so takes a train to Parliament in London. At 7.15pm, she gives a four-minute speech in the Commons – with other MPs in the chamber – during a debate on coronavirus. By her account, she receives a positive result for Covid – but later did not state whether she received the diagnosis before or after addressing MPs. She asks SNP whips for a proxy vote, saying a family illness means she has to return to Scotland.

SINCE 2015, voters in a constituency have been given the power to “recall” their local MP and force a by-election – but only in very limited circumstances.

Constituents are not allowed to initiate proceedings. It can only happen if an MP is found guilty of wrongdoing that sees them hit with:

A custodial prison sentence of a year or less. Longer sentences disqualify MPs without the need for a petition.

Suspension from the Commons for at least 10 sitting days or 14 calendar days, following a report by the Committee on Standards.

A conviction for providing false or misleading expenses claims.

In these circumstances, voters can attempt to force an MP out but need to gather support from at least one in 10 voters in a constituency.

Successful petitions force the recalled MP to vacate the seat. To date there have only been three petitions

made.