Humza Yousaf has demanded the Scottish Conservatives apologise for previously backing Boris Johnson "to the hilt".
The disgraced former prime minister was found to have deliberately misled the House of Commons over Partygate in a damning report issued by MPs today.
Johnson would also have faced a humilating 90 day suspension from Westminster if he had not chosen to resign last week.
Yousaf described it as a "dark chapter" in the history of the UK parliament and accused the former Tory leader of "betraying every single person in this country".
Johnson was slammed in the report after he and his aides were found to have repeatedly flouted covid lockdown rules when in Downing Street during the height of the pandemic in 2020.
Yousaf said: "This is an extraordinary dark chapter in Westminster's history.
"I am thinking primarily of all of those who lost loved ones during covid, of those couldn't attend a funeral because of the restrictions in place during lockdown, those who couldn't hold the hand of a loved one because of the restrictions that were in place.
"Boris Johnson has not just betrayed the House of Commons but has betrayed every single person in this country."
The report by the cross-party privileges committee is expected to be voted on my MPs next week.
And Yousaf challenged all Tory MPs - including Douglas Ross - to support sanctions against Johnson.
He added: "The Scottish Conservatives, who backed Boris Johnson to the hilt, who invited him to their party conference, they should not only apologise for that full backing, but it is incumbent that when this report is brought to the House of Commons, that every Scottish Conservative MP votes to sanction Boris Johnson."
Stephen Flynn also challenged Rishi Sunak to impose tougher sanctions on Johnson following the report.
The SNP leader a Westminster said: "The damning report into Boris Johnson shows he repeatedly lied to the public and parliament. Rishi Sunak must respond with tough action against his disgraced Tory predecessor - removing his taxpayer-funded allowance, binning his honours list, and recouping his legal fees.
"Johnson may be gone from parliament but his toxic legacy lives on."
Speaking to reporters in the Scottish Parliament, Douglas Ross said he would support the recommendations of the committee when the report was presented to the Commons next week.
Asked if his previous support for Johnson was a mistake, the Scottish Conservatives leader said: "No, I think even his harshest critics can also see there were achievements from his time in office."
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