Douglas Ross has announced he will lodge a motion of no confidence in Humza Yousaf as First Minister.
The Scottish Conservative leader said he was making the move hours after the First Minister ended the Bute House agreement with the Scottish Greens, sacking Patrick Harvie and Lorna Slater as ministers.
At First Ministers Question Time today Ross branded Yousaf's leadership as "weak" and said his government had "unravelled".
He told the Scottish Parliament: " I can announce on behalf of the Scottish Conservatives I am lodging a motion of no confidence in Humza Yousaf.
"He is a failed first minister, has focused on the wrong priorities for Scotland and has governed on behalf of the SNP instead of Scotland and is unfit for office."
Yousaf will now lead a minority government after he called time on the coalition deal with the Greens.
The Greens membership were due to vote on whether to continue with the power-sharing deal but Yousaf made the move to end it first today.
The First Minister hit back at the Tories and said the public would judge them at the General Election.
He said: "The Conservatives are nothing if not predictable. There is an opportunity for the opposition to show what they are really made of.
"Do they want to govern in the national interest and collaborate or play political games?"
He cited "living 100,000 children out of poverty, removing peak rail fares and the council tax freeze" as examples of helping people through a cost of living crisis.
Yousaf added: "I'll leave it to Douglas Ross to play the political games. The electorate will give the Conservatives an almighty thumping" at the General election.
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