Andy Maciver has long called for a new centre-right force in Scotland and the chaos of recent events has underlined his view.
The former Scottish Tory communications chief insisted work on a new party should start straight after the local elections in May.
Adam Tomkins, a Scottish Tory frontbench MSP until last year, also wants to see a split.
"What is to stop all 31 Scottish Conservative MSPs resigning from the Conservative Party and saying they have a new whip, and it's called the liberal unionist whip?" he said.
"What's to stop that? That could happen overnight."
It followed the Prime Minister's admission that he attended a gathering in the Downing Street garden during lockdown in May 2020.
Mr Tomkins said there are now two scenarios. The first sees Mr Johnson resigning or being forced out, to be replaced by a "more palatable" figure such as Chancellor Rishi Sunak. This would leave Mr Ross "vindicated".
The second scenario sees Mr Johnson cling to power.
What the Scottish Tory leader does then, said Mr Tomkins, is an "interesting question".
He argued that if the Prime Minister does survive, Mr Ross would be left with "no option, but to lead his party away from the UK Conservative Party in some shape or form".
Mr Tomkins added: "You can't shoot and miss without looking very diminished. Having shot, there have got to be consequences.
"And the consequence either is that Boris goes, or that Douglas does something in consequence of the fact that Boris hasn't gone, having called for it."
Mr Tomkins, a law professor at the University of Glasgow, said: "I think that when it comes to Scottish elections, we should have Scottish parties.
"I think that when it comes to UK elections, it's fine to have UK parties.
"But I think that the centre-right group of politicians in Holyrood should not be called Conservatives and should not be members of the Conservative Party.
"There will always be a close alliance between them and the Conservative Party, but I'm in favour of a clean break."
He argued Mr Johnson has "crystallised" an existing problem with the Tory brand north of the border.
Mr Maciver said the Scottish Tory leader faces an "astonishingly simple" choice – he either continues with the status quo or he creates a party that could win Holyrood elections.
A new centre-right party for Holyrood
He said the Conservatives could continue to stand candidates in Scotland for UK general elections.
But there should be a "completely different party" for the Scottish Parliament.
"As soon as the May local elections are over, it would be the perfect time for it to happen, right then," he said.
"Because you then have a clear four years from that point on till you get the next Scottish Parliament election.
"It's a long enough time to have this work, to have it sit."
Mr Maciver previously worked on Scottish Tory MSP Murdo Fraser's bid for the leadership in 2011, in which he argued for a new party.
"Funding wouldn't be a problem," Mr Maciver insisted. "That's the one thing that was never a concern.
"The sort of money that's floating around for a Scottish-only centre-right party is very significant – former Tory funders in some cases, and in some cases former SNP funders.
"Certainly when we were doing Murdo's campaign ten years ago, the one thing that was never a concern was money. There was loads of it."
He said the existence of the Scottish Conservative Party in its current form is a "massive threat to the union" because of its links with the damaging situation down south and its "inability to strengthen the centre-right movement in Scotland".
A revealing insult
Following Mr Ross's resignation call on Wednesday, Jacob Rees-Mogg, the Tory leader of the House of Commons, described him as “quite a lightweight figure”, sparking a furious row.
Mr Maciver, who still works in communications, said he believed the insult was co-ordinated by Downing Street.
"That is authorised by Downing Street, as far as I'm concerned," he said. "I think that's a co-ordinated attack, at that point."
In terms of what happens next, the insult was actually the most important thing to happen on Wednesday, he argued, “because that is life for the Scottish Tory party and it has been for 20 years, and it will be for the next 20 years as well if they don't change something”.
Mr Maciver added: "There are lots and lots and lots of people in the Tory Party, in London especially, but throughout England, who think in exactly the way that Jacob Rees-Mogg thinks – that the Scottish leader in Holyrood, the leader of the MSPs, doesn't matter.
"That is a very common attitude, that's the reality of it."
Pollster Mark Diffley said there were "dangers" in setting up new parties and it would not be a “risk-free path” in terms of polling and public opinion.
He said: "Look at how it went for [former first minister] Alex Salmond this time last year."
Mr Diffley, the former director of Ipsos MORI Scotland, added: "History is littered with new parties coming and going."
Polling expert Sir John Curtice, a professor of politics at the University of Strathclyde, said: "If you're going to create a separate party and try to persuade voters that this is not the Conservative Party mark two, you would need a lot of time to do that."