Video report by Greg Hoare
Last night, the Leader of the House of Commons, Jacob Rees-Mogg, hit out at the Scottish leader, describing him during an appearance on the BBC's Newsnight programme as "quite a lightweight figure" in the party.
Mr Rees-Mogg also said Scottish Secretary and Dumfries and Galloway MP Alister Jack was a "much more substantial and important figure in this".
Tories in Scotland are speaking out against Mr Johnson - with the overwhelming majority of MSPs having publicly backed Mr Ross and his calls for the PM to quit.
Today at Holyrood, Mr Ross was asked by ITV Border's Scottish political programme Representing Border about the comments.
He replied: "He is entitled to his opinion I do not have to agree with him."
His fellow MSP Jamie Green, who represents the West of Scotland, suggested that Mr Rees-Mogg "should just go and have a lie down" adding: "Preferably not in the House of Commons."
Mr Ress-Mogg's comments were seized upon by Nicola Sturgeon at today's First Minister's Questions in Holyrood. She said the Conservatives "can't even show basic respect to their own colleagues".
Mr Jack meanwhile has backed both Mr Ross and the Prime Minister.
Mr Rees-Mogg though has defended his comments and said the leader of the party in Scotland has "a duty to support the leader of the party nationally
ITV's Northern Reporter Hannah Miller has found out more on this story.