BORIS Johnson has backed Dominic Cummings for breaking lockdown rules, saying he has "acted responsibly, legally and with integrity".

The PM told the daily Downing Street briefing: "He [Cummings] followed the instincts of every father and every parent and I do not mark him down for that."

"In every respect he has acted responsibly, legally and with integrity."

Johnson said that “some” of the allegations about Dominic Cummings’ behaviour during self-isolation were “palpably false”.

“Though there have been many other allegations about what happened when he was in self-isolation and thereafter, some of them palpably false, I believe that in every respect he has acted responsibly and legally and with integrity and with the overwhelming aim of stopping the spread of the virus and saving lives," he added.

“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.”

Initially it was suggested Cummings drove 250 miles between London and Durham despite the guidelines on travelling, and while showing symptoms of coronavirus.

However fresh claims emerged in the Observer and Sunday Mirror that he made a second trip to Durham last month after having returned to work at Westminster.

Nicola Sturgeon has called for him to resign over the issue.

READ MORE: Nicola Sturgeon says Dominic Cummings must go after lockdown breach