Douglas Ross has announced he will resign as leader of the Scottish Conservatives.
He will carry on in the role until after the election and will also resign as an MSP if he is re-elected to Westminster.
It follows a row over Mr Ross standing as a candidate for Aberdeenshire North and Moray East instead of David Duguid, who has been in hospital and was in effect de-selected.
Mr Ross said he originally thought he could continue to serve as an MSP and MP as well as party leader, but said “on reflection, that is not feasible”.
He was the only MSP to also serve as an MP in the current Holyrood session before the UK Parliament dissolved.
Mr Duguid, who had held the Banff and Buchan seat since 2017, had already been adopted by local party members and has disputed suggestions that he is “seriously ill”.
Last week a senior Tory said Mr Ross’s position was not tenable and that his judgement over the situation had been “sorely lacking”.
On Monday, a Scottish Conservative source told BBC News that Mr Ross had come to the realisation that the party’s MSPs would not “put up” with him serving as both an MP and an MSP.
They added that the reaction to him announcing plans to stand in place of Mr Duguid was another factor.
Mr Ross said he was committed to “fighting and winning” the Westminster seat, the boundary for which has been newly drawn.
He said: “Should I be given the honour to represent the people and communities of this new seat, they should know being their MP would receive my complete focus and attention.
“I will therefore stand down as leader following the election on 4 July, once a successor is elected. Should I win the seat, I will also stand down as an MSP to make way for another Scottish Conservative representative in Holyrood.”
Mr Ross also came under pressure at the weekend when the Sunday Mail reported that his own advisers had raised concerns over 28 parliamentary travel claims which may have been combined with his work as a football linesman.
He said the expenses claims were approved by the independent parliamentary body IPSA and he would have “no issue” with the expenses being examined for a second time.
SNS Assistant referee Douglas Ross during a Viaplay Cup Round of Sixteen match between Heart of Midlothian and Partick Thistle at Tynecastle Stadium in August last yearSNS
In 2016, Mr Ross became the MSP for Highlands and Islands via the list system.
Following the unexpected resignation of Jackson Carlaw, he quickly became the leader of the Scottish Conservatives in August 2020.
Mr Carlaw said that a “younger and fresher voice” was needed to lead the party into the next Scottish Parliament election.
At the time Mr Ross was seen as a close ally of Prime Minister Boris Johnson – who spoke to him shortly after he was confirmed as leader – despite opposing Brexit in the EU referendum.
Months prior to this Mr Ross had resigned as a Scotland Office minister over Dominic Cummings, the PM’s chief adviser, refusing to quit for making a trip from London to Durham during the coronavirus lockdown.
When a party leader announces their resignation in the middle of an election campaign, you know something has gone very wrong.
For Douglas Ross, it was replacing the hospitalised David Duguid as his party’s candidate in Aberdeenshire North and Moray West at the general election.
Some were uneasy about the optics of the party leader swooping in when a colleague was ill.
But what had gone down really badly with Conservative MSPs at Holyrood was the plan to continue to try and carry on as both an MP and an MSP.
Douglas Ross had previously promised he wouldn’t do that.
One of his Scottish Tory colleagues told me last week it had been received “like a bucket of cold sick”.
