Boris Johnson's top aide stands his ground on lockdown breach

London | Prime Minister Boris Johnson's top strategist, Dominic Cummings, has launched a defiant defence of his lockdown-busting trip to his family farm in April, rejecting accusations that he had broken rules and refusing to offer regret or his resignation.

An unrepentant Mr Cummings on Monday (Tuesday AEST) convened an hour-long news conference at Downing Street - an almost unprecedented move by a prime ministerial adviser - to explain his actions in travelling some 400 kilometres to his parents' farm at the height of Britain's lockdown in late March.

The weekend revelation that Mr Johnson's high-profile aide had made his own interpretation of the lockdown rules has sparked public fury in Britain.

Accused of white-anting the government's "stay home" guidance and sending a signal that people should feel free to tailor the rules to suit themselves, he is facing calls to resign even from some Conservative MPs.

"There is understandable anger, but a lot of that anger is based on reports in the media that have not been true," Mr Cummings told journalists.

He then provided a blow-by-blow account of how he moved to an isolated cottage on his parents' farm, even as he became symptomatic with COVID-19, on concerns he and his wife might both become too sick to care for his four-year-old son.

He defended himself as acting "reasonably", saying the official lockdown guidance "allowed me to exercise my judgment about the situation I found myself in ... [though] I accept of course that there is room for reasonable disagreement about this".

Mr Johnson later said the public would have to "make their minds up" as to whether Mr Cummings had behaved reasonably.

He said his aide didn't have his "unconditional backing" but rejected assertions the affair had detracted from the government's lockdown messaging.

Mr Cummings was himself asked if his actions undermined or confused the government's message to stay at home, or would encourage people to similarly exercise their own judgment and discretion as he had done.

"The coverage over the last couple of days could encourage people to behave in certain ways," he said, but added he had "no regrets" about his own behaviour.

He provided cover to his boss, saying that he had not discussed his trip in advance with Mr Johnson, and that neither of them could remember much about a subsequent conversation when both men were ill.

The previous night, Mr Johnson had issued a short but strident defence of his svengali, saying he was satisfied Mr Cummings had complied with the official guidance.

But as Mr Cummings left his house for work on Monday, he was greeted by a scrum of media and a handful of protesters, asking if there was one rule for him and another rule for the masses.

One of the government's pandemic advisers, Neil Ferguson, quit earlier this month after his breaches of official lockdown guidance were exposed. Scotland's chief medical officer also had to resign after visiting her rural second home, against official advice.

Mr Cummings said he had not offered to resign, nor considered doing so. "That's up to the Prime Minister, I'm here to try and do the best I can for the government, to try and change the country for the better," he said.

The Prime Minister's right-hand man was the author of the 'Leave' victory in the Brexit referendum, and more importantly a key strategist in helping Mr Johnson win the Conservative Party leadership, deliver Brexit and secure a convincing election victory in December.

Outspoken, eccentric and iconoclastic, Mr Cummings has become an object of fascination to the British media, and a figure whom Mr Johnson's opponents - and even some of his supporters - love to hate.

This has meant that his value to Mr Johnson as a source of political advice is often counterbalanced by the distracting bandwidth he consumes by courting controversy and conflict.

Meanwhile, the easing of lockdown in Britain continues: Mr Johnson said it was likely primary schools would reopen for some years next week, with the retail sector to follow from June 15.