Scottish Conservative leader Douglas Ross said:
"It’s clear the SNP are now running scared of the Michael Matheson scandal.
It’s unacceptable that neither the health secretary nor Humza Yousaf are willing to answer questions on this issue when the former knowingly and repeatedly lied and the First Minister facilitated a cover-up.
Now we discover that Shona Robison was so fearful of having to defend the indefensible that she cancelled her pre-arranged interview.
This scandal is now impacting on the whole SNP government – not just a health secretary who is ditching ministerial engagements to lie low.
The SNP must agree to Scottish Conservative demands for a debate in parliament this week because there are so many key questions that remain unanswered and that’s regardless of whether or not Humza Yousaf finally does the right thing and sacks Michael Matheson.
He simply cannot continue as health secretary, and the longer he does the more his position in government becomes a distraction for Humza Yousaf and the SNP."