The Daily Mirror is reporting that Boris Johnson has doubled down on his defence of top aide Dominic Cummings.

Speaking at the daily Coronavirus briefing, the Prime Minister addressed questions over whether Mr Cummings had broken the rules and “endangered lives.”

He claimed that he had not, despite his strategy chief travelling 260 miles to a Durham hideaway when his wife had coronavirus symptoms.

Mr Johnson said Mr Cummings had travelled to “try to find the right kind of childcare.”

He said: “I have had extensive face-to-face conversations with Dominic Cummings and I have concluded that in travelling to find the right kind of childcare, at the moment when both he and his wife were about to be incapacitated by coronavirus – and when he had no alternative – I think he followed the instincts of every father and every parent.

“And I do not mark him down for that.”

He added: “I believe that in every respect he has acted responsibly and legally and with integrity.”

Mr Johnson claimed some of the allegations made about Mr Cummings’ movements were “palpably false”, though he offered no evidence for this assertion and did not specify which allegations he was referring to.

Asked why Mr Cummings needed to travel to Durham when he has now said that his family did not care for his son, Mr Johnson said: “The guidance makes it very clear that where you have particular childcare needs that has got to be taken into account.”

He added: “I have seen a lot of stuff in the last few days about this episode of self-isolation by Mr Cummings that does not seem to correspond remotely with reality.”

Again, he provided neither evidence, nor specifics.

He went on: “As far as I can see he stuck to the rules and he acted legally and responsibly with the sole objective of avoiding such contact as would spread the virus.

“His object was to stop the spread of the virus and he behaved in such a way as to do that.”

It comes after the Mirror revealed Mr Cummings had defied lockdown rules for a second time – breaking rules he helped draw up.

The PM’s top aide was spotted in Houghall Woods a fortnight after the first sighting.

He was first spotted in Durham on April 5 while self isolating with the coronavirus.

A return to London saw him back at work on April 14. But by April 19 he was back in Durham.

On the second visit, fellow walkers spotted Mr Cummings at the local beauty spot.

The adviser – tonight facing growing calls to quit – claimed Mr Cummings commented as he passed by: “Aren’t the bluebells lovely?”

Robin Lees, 70, a retired chemistry teacher from Barnard Castle, claimed he saw Mr Cummings and his family walking by the River Tees in the town before getting into a car around lunch time on April 12.

Although he may have completed his period of self-isolation, strict lockdown rules were still in place and the family were 30 miles from his parents’ home.

Asked about this allegation, Mr Johnson said: “I have looked at them carefully and am content that at all times in his period of isolation, actually on both sides of that period, [Cummings] behaved responsibly and legally”.

Yesterday, Mr Johnson offered his “full support” to his chief adviser.

The Mail on Sunday has reported that, in standing by his aide, Mr Johnson said: “It’s not like he was visiting a lover.”

He also reportedly said that he considers the matter closed, as “Dominic had acted within the guidance and was simply caring for his family”.

But the reports have prompted fury from opposition MPs, with the SNP’s Westminster leader Ian Blackford calling for him to be immediately axed.

“It is clear that Boris Johnson must sack Dominic Cummings,” he said on Twitter.

“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.”

Labour, the SNP and the Liberal Democrats have 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?