An online petition calling for Dominic Cummings to be sacked has attracted more than 250,000 signatures.
Boris Johnson's most senior advisor faced an intense backlash over the weekend after it was revealed he had travelled from London to Durham during lockdown - despite helping draft the UK Government's public guidelines in response to the pandemic.
Cummings was backed by the Prime Minister in a shambolic press conference yesterday, nearly 48 hours after claims were published about his travels during lockdown.
A petition calling for the adviser to be dismissed has now a quarter of million signatures - with the SNP's Westminster leader among those sharing it on social media today.
Ian Blackford said: "Boris Johnson must sack Dominic Cummings. If he doesn't this will go on for many weeks and cause lasting damage to public confidence in the Tory government and its Covid-19 response.
"The Prime Minister's judgement is on now the line - he must stop treating the public as fools. There cannot be one rule for Tory advisers and another for everyone else.
"Dominic Cummings broke the rules and he is now threatening public health. He must go without further delay.
"Public anger is palpable. MPs are receiving hundreds of emails from their constituents and hundreds of thousands have signed a petition calling for Mr Cummings to go.
"The police have launched an investigation. This is not going away - however much Boris Johnson arrogantly dismisses the widespread public concern."
Earlier, Nicola Sturgeon accused Boris Johnson of putting political interest ahead of public interest in a damning verdict on his support for a controversial adviser.
The First Minister said she is “very concerned” that backing Cummings for breaking travel restrictions undermines life-saving guidance.
“I say this with a very heavy heart - I really do fear that Boris Johnson has decided to put political interest ahead of the public interest,” she told BBC Radio’s Good Morning Scotland.
Downing Street insists it was understandable to seek childcare at his family’s home in Country Durham around 250 miles away.
It was also claimed Cummings made repeat trips including visiting Barnard Castle 30 miles from Durham.
