Douglas Ross says the SNP civil war over Alex Salmond is “running out of control” and risks trashing the international reputation of Scotland.
The Scottish Tory leader said the “scandals and sleaze dominating the corridors of power” are undermining Holyrood and the Crown Office.
His comments come just hours before Mr Salmond is due to appear before MSPs over his claims of a “malicious and concerted” conspiracy against him.
The former first minister is to appear at the Scottish Parliament as part of an inquiry into the government’s mishandling of sexual harassment complaints about him.
The four-hour session is expected to focus on that botched probe and the accusations made by Mr Salmond.
In a speech to party members Mr Ross said the saga is a “crisis engulfing Scotland”.
He added: “This is an internal party civil war that is running out of control, taking down our country with it.
“The SNP are dragging down the reputation of the Scottish Parliament and our treasured institutions.
“I can only imagine what people abroad are thinking when they look to Scotland today and see the state of our nation.
“The Crown and Parliament at war. Scandals and sleaze dominating the corridors of power. A great country split in two, increasingly divided against itself, broken apart by the SNP.
“A Scotland they don’t recognise, with leaders past and present who are not genuine, sincere or honest. The state of our nation is not healthy.”
Mr Ross also used his speech to hit out at the Scottish Labour Party, which is due to elect a new leader on Saturday.
He said: “Whoever wins, Labour will be half-hearted on the constitution.
“Either Monica Lennon will make the SNP’s arguments for them or Anas Sarwar will tell the SNP ‘not today but tomorrow is fine’ for your indyref2.”