The leader of the House of Commons instead named Alister Jack, Secretary of State for Scotland, as a ‘really serious and senior figure’.
Rees-Mogg’s comments come as Scottish Conservative leader Douglas Ross told Boris Johnson he must resign after the Prime Minister admitted attending a lockdown party in Downing Street.
In an interview with LBC, Jacob Rees-Mogg said: "I don’t think it’s a surprise Douglas Ross takes this view.
"He’s never been a supporter of the Prime Minister. He has constantly made disobliging comments about the Prime Minister.
"I don’t think Douglas Ross is a big figure. I think Alister Jack is a really serious and senior figure.
"He has been constantly in opposition to the Prime Minister”
Addressing Rees-Mogg’s comments, Ian Blackford MP said: “That’s what senior Tories think of their Scottish branch office manager - imagine what they think of the rest of us.
"It’s time for Scotland to be an independent country - and escape the arrogant, corrupt and broken Westminster system for good.”
The SNP Westminster group leader also accused Michael Gove of ‘belittling’ his fellow Conservative colleague Douglas Ross after it was reported that he told the 1922 committee that Mr Ross ‘is in Elgin’ when asked about his recent stance on the Prime Minister resigning.
Mr Gove stated: “My instant response is he’s in Elgin and the national Tory leader is in London.”
Mr Blackford said: “This snide and arrogant remark from Michael Gove, belittling Douglas Ross, underlines the disdain senior Tories hold for Scotland.
"That they dismiss the views of their own branch office so easily is yet another telling insight into the appalling Westminster attitude to Scotland.”
The fall out follows Boris Johnson telling MPs he had attended a “bring your own booze” gathering in the garden of No.10 on May 20, 2020 – during the UK’s first lockdown – for around 25 minutes to “thank groups of staff”.
Mr Johnson, who made the admission at Prime Minister’s Questions on Wednesday despite having previously denied all knowledge of the party, insisted he believed it had been a “work event” as he acknowledged the public “rage” over the incident.