Conservative Murdo Fraser has called for MPs such as Scottish party leader Douglas Ross to help push Boris Johnson from office.
The Mid-Scotland and Fife MSP – who is a frontbench spokesman for Mr Ross at Holyrood – said he would “vote for change” if he were at Westminster.
Mr Fraser is the latest to join fed-up party members hours after Mr Johnson was told he faces a confidence vote.
Earlier, former Scottish Conservative leader Ruth Davidson backed English MP Jesse Norman for publishing a comprehensive take-down of the prime minister’s record.
Mr Ross – who is an MSP and MP – has yet to confirm how he will vote this evening.
He is expected to outline his position later this afternoon.
However, he had called for Mr Johnson to quit in January – before changing his mind in time for the local elections.
Urging MP colleagues to “vote accordingly”, Mr Fraser said: “I don’t have a vote in tonight’s ballot in the House of Commons, but if I did I would be voting for change, and I would urge MP colleagues to vote accordingly.
“The country needs a fresh start under new Conservative and Unionist leadership.”
The threshold of 54 MPs submitting letters to the backbench 1922 Committee to force a vote on Boris Johnson’s leadership was passed on Sunday, chairman Graham Brady said.
The secret ballot was scheduled for Monday evening.
Scottish Secretary Alister Jack said he will support the prime minister.
Mr Jack, unlike others in the Scottish Tories, has been steadfastly behind the prime minister throughout his tenure.
‘Full support’
“The prime minister has my full support, and I will be voting to back him tonight,” he said on Monday.
“He is showing tremendous leadership as we face major challenges at home and abroad.
“I have no doubt that my colleagues in the Parliamentary party will vote to show their confidence in the prime minister.”
Last week we asked each Scottish Tory MP to answer a straight question: Should Boris Johnson resign?
The question had been asked repeatedly by our readers who were also getting frustrated at a lack of clarity.
MPs who failed to respond to our request were Andrew Bowie, David Duguid, John Lamont and David Mundell.
Some had come voiced their anger but stopped short of saying he should go.
Mr Ross flip-flopped on the decision. He had called for the PM to go in January when lockdown parties emerged.
U-turn
But he changed his mind and said Mr Johnson should stay because of a need for stability.
Then he suggested Mr Johnson might go after the war in Ukraine ends.
Former Aberdeen Tory MP Ross Thomson, who helped Mr Johnson into power, said the PM might still have to go even if he wins the confidence vote.
In an analysis, he wrote: “Put it this way. History shows that Tory leaders who face a confidence vote rarely survive. They are either forced to resign or lose a general election.”
#NoConfidence vote thoughts.
In Dec 2018 I was part of the shadow whipping operation to oust Theresa May.
It’s clear from that experience that MPs will tell you one thing but do another. However, the result we predicted was very close to the actual result of 200 to 117.
1/7
— Ross Thomson (@RossThomson_Abz) June 6, 2022
Ms Davidson – now a peer – meanwhile shared a letter by English Tory MP Jesse Norman, stressing “how right” he is.
In the correspondence sent directly to Mr Johnson, the MP described the plan to send some asylum seekers to Rwanda as “ugly”.
He claimed plans to change the Northern Ireland protocol are “economically very damaging, politically foolhardy and almost certainly illegal”.
And he accused the prime minister of presiding “over a culture of casual law-breaking”.
Other Tory MSPs who have called for the prime minister to resign are north-east MSP Douglas Lumsden and Highlands and Islands MSP Edward Mountain.
‘Should Boris Johnson resign?’ Scottish Tory silence to the big question
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