Boris Johnson is under pressure to sack his chief aide after it was reported he and his wife breached the UK’s lockdown by traveling across England to stay with his parents, while showing symptoms of coronavirus.

Dominic Cummings drove more than 260 miles (420 km) from London to Durham, where he stayed with family members just days after Johnson put the UK into lockdown and banned family visits, an investigation by The Guardian and Daily Mirror found.

Police confirmed they attended a property in the area and spoke to an individual about the UK’s lockdown rules on March 31, PA Media reported. Downing Street has declined to comment.

“If (the media reports are) accurate, the Prime Minister’s chief adviser appears to have breached the lockdown rules. The government’s guidance was very clear: stay at home and no non-essential travel,” a Labour party spokesperson said.

“The British people do not expect there to be one rule for them and another rule for Dominic Cummings. Number 10 needs to provide a very swift explanation for his actions.”

The leaders of the Scottish National Party and Liberal Democrats called on Cummings, who played a senior role in the pro-Brexit campaign in 2016 and joined Boris Johnson in Downing Street last year, to resign or be sacked.

And David Lidington, Theresa May’s deputy while she was prime minister told the BBC: “There's clearly serious questions that Number 10 are going to have to address, not least because the readiness of members of the public to follow government guidance more generally is going to be affected by this sort of story.”

The UK’s coronavirus restrictions made clear that people must not visit any other household, including second residences or family homes, and must not carry out any non-essential travel.

“You should not be visiting family members who do not live in your home,” the rules stated. “You should keep in touch with them using phone or video calls.”

The country’s self-isolation guidance also states that if a person has symptoms of Covid-19, they must not leave their home for seven days.

On April 25, Cummings’ wife Mary Wakefield wrote a column in The Spectator magazine about the pair’s experience with Covid-19, but made no mention of traveling outside the capital.

“My husband did rush home to look after me,” she wrote in the piece. “After the uncertainty of the bug itself, we emerged from quarantine into the almost comical uncertainty of London lockdown,” she added.

Cummings showed symptoms shortly after Johnson revealed he had tested positive for the coronavirus.

The PM later spent a brief period in intensive care with the virus. He has repeatedly urged people to stay at home. Neil Ferguson, a leading epidemiologist who advised the UK government on its coronavirus response, was forced to resign earlier this month after it emerged he also broke the lockdown rules.

Scotland's chief medical officer, Catherine Calderwood, also left her position last month after she was photographed by a Scottish newspaper near her family's second home, in a different part of the country to her Edinburgh address.