Douglas Ross announced today that he is to resign as Scottish Conservative leader after the General Election but who succeeds him and when exactly won't be known for at least several weeks.

The timescale will be determined over whether the group of Tory MSPs coalesce around a single candidate or whether more than one contender to replace Mr Ross comes forward.

In the event of the former, it's likely that the new leader will be unveiled shortly after the Westminster election, maybe even days later. 

Should a contest be called, it could be weeks or possibly even a couple of months before Mr Ross's successor is in place as the candidates put themselves forward formally and a race begins. In that events hustings would take place, probably over the summer Holyrood recess, and the party's members north of the border would vote for their preferred candidate.

READ MORE: Who could replace Douglas Ross as Scottish Tory leader?

Mr Ross was himself appointed to the role unopposed in August 2020 without a contest after the sudden resignation the previous week of Jackson Carlaw.

He had emerged as leader-in-waiting within hours of Mr Carlaw’s resignation which came in a bloodless coup orchestrated by party leaders after several opinion polls showed a surge in support for the then SNP leader and First Minister Nicola Sturgeon and for independence.

At the time of becoming Scottish Tory leader, Mr Ross was the MP for Moray and did not sit in Holyrood so he worked alongside the former party leader Ruth Davidson, then the MSP for Edinburgh Central who acted as his de facto deputy in the Scottish Parliament and had the role of pressing Ms Sturgeon at First Minister's Questions every week.

Mr Carlaw succeeded Ruth Davidson in February 2020 in a contest against former MSP Michelle Ballantyne. 

READ MORE: As Douglas Ross quits as Tory leader, where did it all go wrong?

He had served as acting leader of the Scottish Conservative Party from September 2018 to May 2019 during Ms Davidson's maternity leave and from August 2019 to February 2020 following Ms Davidson's resignation as leader.

Ms Davidson herself became Scottish Conservative leader in 2011 following a contest against the party's then deputy leader Murdo Fraser. He is now the party's spokesman on business, the economy and tourism in Holyrood.

Mr Ross announced today he is to step down as he faced an internal party backlash against his decision to U-turn and stand again for Westminster and his resignation is believed to be the first time that a UK political leader has quit during a Westminster campaign.

The MSP had previously pledged to leave the House of Commons and focus on leading the Tories at Holyrood but prompted fury by instead declaring on Thursday that he would run for the Aberdeenshire North & Moray East constituency.

This followed the Scottish Conservative board sacking David Duguid, the incumbent candidate, who had been reselected by local party members, because of his ill health.

Russell Findlay, the justice spokesman, is said to have “support across the party” and will be encouraged to stand by multiple senior figures. He has repeatedly denied having ambitions for the leadership.

A former investigative and crime reporter, Mr Findlay has had a meteoric rise in the party at Holyrood. Despite only being elected for the first time in 2021 after almost three decades working in newspapers, he's already been tipped by many as the next Scottish Tory leader.

Other potential frontrunners could be Craig Hoy, the party chairman, Jamie Greene, the former justice spokesman, and Stephen Kerr, the former chief whip, who is also standing for a Westminster seat.

Other candidates could include Mr Fraser, the economy spokesman, Meghan Gallacher, the deputy leader, Liam Kerr, the education spokesman, and Maurice Golden, the former chief whip, although multiple MSPs said there was little desire for people to publicise their intentions before the election.

Whether chosen by the Tory MSPs or elected by the wider party, whoever succeeds Mr Ross will face a challenge in getting the Scottish Conservatives ready for the 2026 Holyrood election with polls suggesting the party could move from being the second biggest party in Holyrood to the third amid a resurgent Labour and fall in support for the SNP.