British Prime Minister Boris Johnson’s closest aide says he does not regret driving 400 kilometres from London to get childcare when Britons were being told to stay at home to fight COVID-19.

Dominic Cummings is refusing to step down amid growing calls for his resignation for allegedly breaching national coronavirus restrictions.

It comes as police confirmed they were investigating further complaints about Mr Cummings’ travel during Britain’s nationwide lockdown.

It has also emerged that as well as travelling to northern England, the Cummings family took a day trip to a tourist attraction.

“I don’t regret what I did … I did what I thought was the right thing to do,” Mr Cummings said at a briefing, after reading a statement defending his decision to travel to Durham with his wife, who was ill at the time, and his four-year-old son.

“I think … I behaved reasonably.”

In an extraordinary scene in the rose garden at 10 Downing Street, Mr Cummings, 48, sat at a desk on the grass for an hour, subjecting himself to detailed questions from reporters.

Quizzed about a drive he took with his wife and four-year-old son from the family farm in northern England to Barnard Castle, Mr Cummings said his eyesight had been affected by illness and he wanted to test whether it would be good enough to drive back to London.

MPs, church leaders, police officers and scientists agree that Mr Cumming’s trip to Durham has damaged citizens’ trust in public health messaging.

Mr Johnson’s own judgment has been called into question for defending Mr Cummings in a move that left many in Britain slamming what they saw as hypocrisy from the country’s elite.

Britons have been sharing heartbreaking stories of sacrifices made during tough lockdowns – including missing saying goodbye to dying loved ones – to show how it appears different rules apply to the people in charge.

Demonstrators near the home of Downing Street aide Dominic Cummings. Photo: Getty

Mr Cummings did not apologise for the trip and said he took the journey soon after learning that Mr Johnson had tested positive for the coronavirus.

He said his wife, Mary Wakefield, was already ill and he feared if he also got sick, neither would be strong enough to care for their son.

He said he decided they should go and stay in an isolated cottage on his father’s farm so that his 17-year-old niece could look after their son if necessary.

Mr Cummings did get sick while they were there, as did his son, who briefly went to hospital.

A protester outside Mr Cummings’ London home. Photo: Getty

Asked whether he tried to find childcare in London before leaving, he said he did not think it would have been reasonable to ask friends to expose themselves to the virus.

Mr Johnson came out fighting for Mr Cummings on Sunday but his intervention backfired after he failed to provide any detailed justification for his adviser’s actions.

With a growing number of MPs from his own Conservative Party openly defying him by calling on Mr Cummings to quit, Mr Johnson asked his trusted aide – who normally stays behind the scenes – to explain himself in public.

-with AAP