Yesterday Mr MacDonald joined calls for Mr Cummings himself to resign after it emerged he had repeatedly broken government lockdown rules he himself had helped bring into force.
Over the weekend it emerged Mr Cummings drove his family 264 miles to his parents’ estate in Durham while his wife was suffering coronavirus symptoms.
However, since Mr Cummings did not resign Mr MacDonald is now switching his attention to the Prime Minister and asking him to do the right thing and give the advisor the heave.
Mr MacDonald’s new approach to the situation follows a press conference in the Downing Street garden last night when, instead of resigning, Mr Cummings admitted to a series of further breaches of lockdown.
He refused to apologise or even accept he had undermined the essential public health message people who have the virus should stay at home.
Mr MacDonald said: “People in Falkirk district have made huge sacrifices over the months to obey the rules, while Boris Johnson's most senior adviser was breaking them on multiple occasions.
"He should have resigned but instead he showed no contrition and refused to say sorry for his behaviour which has left millions of people, who have been sticking to the rules, justifiably furious.
“Cummings’ double standards are breath taking. His convoluted excuses to justify his inexcusable behaviour were frankly insulting to the people of Falkirk district.
“The Prime Minister has no option but to sack Mr Cummings. His failure to do so by now is a failure of leadership that could have a catastrophic effect on how coronavirus is contained.
“As Scottish Tory leader Jackson Carlaw said: 'There cannot be one rule for bosses and another for everyone else'. People must have confidence that the Tory government is following its own rules – not protecting advisors who break them.
“Boris Johnson has apparently known about this for weeks, has failed to offer any answers himself and now has no option but to sack Dominic Cummings and answer questions about his own role in the Downing Street cover-up.
“Leading public health experts have warned this failure of leadership is damaging the public health message and putting lives at risk. The longer the Prime Minister allows this farce to continue the more the Tory government will lose credibility and respect.
“He must sack Mr Cummings without further delay.”
Mr MacDonald said the message in Scotland has remained the same throughout.
“In Scotland, the clear public health advice has not changed. The Scottish Government will review the current rules on Thursday and hopefully this will lead to a gradual easing of some restrictions, evidence permitting.
“But for now, people in Falkirk district should continue to stay at home – it really is helping to save lives.”