A fierce row over the actions of the Prime Minister’s top aide continues on Sunday as Dominic Cummings faces more allegations that he broke lockdown rules.

Boris Johnson is under renewed pressure to sack Mr Cummings after reports surfaced that the 48-year-old made a second trip to County Durham, where his family lives, despite social restrictions.

The PM pledged his “full support” on Saturday to his under-fire chief adviser, who it emerged had travelled 260 miles to the North East in March to self-isolate with his family while official guidelines warned against long-distance journeys.

According to the Sunday Times, the Conservative Party leader told allies he would not throw Mr Cummings “to the dogs” following reports he made the journey to ensure his four-year-old child could be looked after as he and his wife were ill.

But according to reports in the Observer and Sunday Mirror, the former Vote Leave campaign co-ordinator made a second trip to Durham and was seen there on April 19 – five days after being photographed on his return to Westminster.

A second eyewitness told the two papers they saw him a week earlier in Barnard Castle on Easter Sunday, a popular tourist location 30 miles away from Durham, during the period he was believed to be self-isolating.

Downing Street has said it would “not waste time” replying to the fresh allegations from “campaigning newspapers”.

Transport Secretary Grant Shapps, who was sent out to defend Mr Cummings at the daily Downing Street coronavirus briefing on Saturday, will face further questions over the latest developments when he represents the Government during the Sunday morning political television programmes.

As well as Mr Shapps, a host of senior Cabinet ministers – including Health Secretary Matt Hancock and Attorney General Suella Braverman – issued statements of support for Mr Cummings on social media.

In a statement on Saturday morning, Number 10 said Mr Cummings had travelled to be close to family to seek help looking after his four-year-old child after his wife became ill with coronavirus symptoms – a virus which has seen more than 45,000 people in the UK die after contracting it, according to the latest available data.

Speaking at the press conference, Mr Shapps added that Mr Cummings had “stayed put for 14 days” while residing at a family property, having pre-empted his own illness once his wife showed Covid-19 symptoms.

But the trip to Barnard Castle on April 12, if correct, would call that testimony into question.

According to the papers, 70-year-old retired teacher Robin Lees, of Barnard Castle, said he saw Mr Cummings and his family walking by the River Tees near the town.

He told the Mirror and Observer: “I was a bit gobsmacked to see him, because I know what he looks like.

“It just beggars belief to think you could actually drive when the advice was stay home, save lives. It couldn’t have been clearer.”

The papers also reported that a second unnamed source recalled seeing Mr Cummings in woodland near his family’s Durham property on April 19, recognising him due to him wearing his trademark beanie hat.

He reportedly was heard commenting on how “lovely” the bluebells were during an early-morning Sunday stroll with his journalist wife Mary Wakefield.

The claims prompted fury among MPs, and Ian Blackford, SNP Westminster leader, renewed his calls for the PM to axe Mr Cummings from his team.

He wrote on Twitter: “It is clear that Boris Johnson must sack Dominic Cummings.

“When the PM’s top adviser ignores the Government’s instruction to the public not to engage in non-essential travel he has to leave office. Immediately.”

A Labour source questioned why senior ministers had defended Mr Cummings in light of the fresh allegations.

Culture Secretary Oliver Dowden tweeted shortly after the daily press conference had finished, saying: “Dom Cummings followed the guidelines and looked after his family. End of story.”

Labour has, along with the SNP and the Liberal Democrats, written to Cabinet Secretary Sir Mark Sedwill demanding an inquiry into what happened.

A Labour source said: “If these latest revelations are true, why on earth were Cabinet ministers sent out this afternoon to defend Dominic Cummings?”

Acting Lib Dem leader Sir Ed Davey said the PM’s judgment would be called into question if he did not give Mr Cummings the chop.

“Surely Boris Johnson must now recognise the actions of his top adviser are an insult to the millions who have made huge personal sacrifices to stop the spread of coronavirus,” said the former energy secretary.

Responding to the allegations, a No 10 spokeswoman said: “Yesterday the Mirror and Guardian wrote inaccurate stories about Mr Cummings.

“Today they are writing more inaccurate stories including claims that Mr Cummings returned to Durham after returning to work in Downing Street on 14 April.

“We will not waste our time answering a stream of false allegations about Mr Cummings from campaigning newspapers.”

In other news:

– The PM is set to reveal plans to ease restrictions for certain sectors of the economy – with the changes expected to signal the reopening of non-essential shops – when Cabinet meets on Monday, according to Government sources.

– Test and tracing is set to commence at the end of this week, with 25,000 contact tracers in place – although the associated NHS Covid-19 symptoms tracking app will not be ready at the same time.

– A decision to fast-track £160 million-worth of support for rough sleepers will see 3,300 homes built in the next 12 months in a bid to prevent the 5,400 rough sleepers taken off the streets returning to homelessness once the pandemic is over.

The latest wave of lockdown infringement allegations against Mr Cummings came as a row between Durham Constabulary and No 10 intensified.

The force put out a fresh statement standing by earlier assertions that officers spoke with family members of Mr Cummings, only for the Government to deny it.

A new statement from the constabulary said the Leave campaigner’s father had a conversation with officers after he requested to speak to them.

Durham Police said: “During that conversation (with officers), Mr Cummings’ father confirmed that his son had travelled with his family from London to the North East and was self-isolating in part of the property.”