British Prime Minister Boris Johnson on Tuesday faced a mounting internal rebellion, including a ministerial resignation, over a scandal around his top aide Dominic Cummings taking a cross-country trip during the coronavirus lockdown.

Dozens of Conservative lawmakers have now demanded the controversial adviser quit or be sacked while Douglas Ross, a minister for Scotland, resigned in protest, as a political crisis that has dominated the headlines for days continued unabated.

"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," Ross said in a statement.

Dominic Cummings defended his travel during lockdown despite mounting calls for his resignation Dominic Cummings defended his travel during lockdown despite mounting calls for his resignation Photo: POOL / Jonathan Brady

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

The government said it regretted his decision, but the resignation piled more pressure on it and Cummings.

He held a press conference Monday to justify driving his wife and young son on a 264-mile (425-kilometre) trip from London to Durham in northeast England in late March during the height of the coronavirus crisis.

Earlier that week Johnson had introduced a stringent lockdown requiring people to stay at home -- barring exceptional circumstances -- or face fines.

British Prime Minister Boris Johnson's top aide Dominic Cummings defies calls to resign British Prime Minister Boris Johnson's top aide Dominic Cummings defies calls to resign Photo: UK POOL /

Cummings, who had virus symptoms around the time of the trip while his wife was also suffering from COVID-19, has claimed he complied with the guidance because childcare needs were one such exception.

The Brexit campaign mastermind, a divisive figure within British politics, said he wanted to leave his four-year-old son at his parents' house in case both he and his wife became incapacitated.

There has been widespread outrage at Cummings' alleged lockdown breach, such as the graffiti in north London There has been widespread outrage at Cummings' alleged lockdown breach, such as the graffiti in north London Photo: AFP / DANIEL LEAL-OLIVAS

Health Secretary Matt Hancock was the latest minister to defend Cummings at the daily Downing Street briefing, saying "what he did was within the guidelines".

But following a question from a priest during the briefing -- members of the public are allowed to ask a question each day -- over whether anybody fined for being outside their homes due to childcare issues would now be reimbursed, he pledged the government would review the matter.

"Especially coming from a man of the cloth, I think that is a perfectly reasonable to take away that question," Hancock said.

The priest, Martin Poole, later told Sky News he would like to see those in government "treated in the same way as everybody else".

Cummings was already a lightning rod for many Britons over his role in orchestrating the 2016 Brexit campaign Cummings was already a lightning rod for many Britons over his role in orchestrating the 2016 Brexit campaign Photo: AFP / Tolga AKMEN

The prime minister has called Cummings' actions "plausible".

But Jackson Carlaw, the leader of the Conservatives in Scotland, said his most trusted adviser should consider quitting.

"Given the furore, given the distraction this is... if I were Mr Cummings I would be considering my position," he told STV News.

Carlaw's comments followed a rising tide of calls from fellow Tories for the adviser to go, with MP Mark Pawsey saying he had acted "against the spirit of the lockdown".

Meanwhile, a host of smaller opposition parties wrote to Johnson to call for Cummings' ousting.

"There cannot be one rule for those involved in formulating public health advice and another for the rest of us," the Scottish National Party, Liberal Democrats, Plaid Cymru and others said in the letter.

The main opposition Labour party has stopped short of backing that call but demanded an internal government inquiry.

Britain has been one of the worst-hit countries by the pandemic, with more than 46,000 deaths attributed to COVID-19 by mid-May, according to official statistics released Tuesday.

Johnson's government, whose less comprehensive tally updated daily has counted 37,048 fatalities, has been heavily criticised for its response.

The Cummings controversy appears to have further damaged its reputation, with the latest YouGov poll showing 59 percent of respondents thought he should resign, up from 52 percent.

Cummings has also resisted calls to resign, telling reporters on Monday that he acted "reasonably and legally".

"I don't regret what I did," he added.