SCOTTISH Tory leader Jackson Carlaw is now facing an open rebellion after four of the most senior members of his Holyrood team broke ranks over the Dominic Cummings saga.

Murdo Fraser, Donald Cameron, Graham Simpson and Adam Tomkins have spoken out over the Prime Minister's decision not to sack his chief aide – despite their boss Carlaw insisting it is a matter for Boris Johnson.

The three men are central figures in Carlaw's frontbench team. Fraser covers the constitution portfolio, Cameron, finance, Tomkins the social society brief, while Simpson holds the housing brief.

In correspondence to a constituent, Fraser wrote: "My own personal view on the matter, on the basis of the information currently available, is that Mr Cummings did break the rules, and therefore, as someone who is [in] a position of authority, he should step down from the post."

He added: "I have communicated this view to the Prime Minister through the appropriate channels."

Carlaw initially refused to demand for Cummings to go. “I've heard what the Prime Minister has said and it is a situation for him to judge," he said at the weekend.

The Scottish Tory leader has since called for the PM's top aide to resign.

READ MORE: Jackson Carlaw FINALLY calls for Dominic Cummings to resign​

Douglas Ross, the parliamentary under-secretary of state for Scotland, announced his resignation that he was quitting after hearing Cummings' efforts to defend his trip from London to Durham.

The first resignation over the allegations rocking the Government came as Cabinet Office Minister Michael Gove sought to defend his longstanding ally as having acted in an "entirely reasonable" way, and within the law.

But Ross, the MP for Moray, said that "while the intentions may have been well-meaning", Cummings' interpretation of the rules was "not shared by the vast majority of people".

"I have constituents who didn't get to say goodbye to loved ones; families who could not mourn together; people who didn't visit sick relatives because they followed the guidance of the Government," the Tory MP for Moray wrote.

"I cannot in good faith tell them they were all wrong and one senior adviser to the Government was right."

Cameron supported Ross's decision to resign. Responding to his announcement on Twitter this morning, Cameron wrote: "Well done, my friend.”

Tomkins, a Glasgow MSP, was the first senior Scots Tory to speak out this morning – saying losing Ross from the UK Government was a “disaster”.

Tomkins tweeted: “It shows exactly why Cummings should be sacked. I suspect others will follow where Douglas has led.”

A fourth Scottish Tory shadow cabinet member Graham Simpson also broke ranks and called for the PM's chief aide to go.

“I don’t like calling for people to resign or be sacked – there is too much of that. I tend to believe in giving people the chance to say sorry and learn. In this case though I think Mr Cummings should go,” he wrote.

READ MORE: Nicola Sturgeon: Douglas Ross resignation was 'fair play'

A No 10 spokesman said Johnson "regrets" Ross's decision to quit.

The resignation came amid continued concerns over how the Prime Minister's defence of Cummings will affect the public, police and health workers during the pandemic.

In an extraordinary press conference for an adviser, Cummings argued that his journey to Durham in March was justified as he sought to protect his family's health.

But many questions remained unanswered, including over his subsequent drive to Barnard Castle which he said was to test his eyesight after it was affected by Covid-19.

Former Greater Manchester Police chief constable Sir Peter Fahy said officers had become "frustrated" by the fiasco, which may hinder policing with the rules "now very confused".

And he suggested that Cummings' trip to Barnard Castle "certainly appears to be against the Highway Code - it's not the way to test your eyesight, and put potentially other people in danger".

He also said "it may well be that absolutely he'd have been turned back" by officers if they stopped him during the drive north from London in March.