U.K. Prime Minister Boris Johnson came out in support of top aide Dominic Cummings Sunday after a joint investigation by the Daily Mirror and The Guardian found Cummings had traveled 260 miles in April to visit his parents while exhibiting coronavirus symptoms.The latest: "In traveling to find the right kind of child care, at a 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," Johnson said Sunday."And while there have been many other allegations about what happened when he was in self-isolation and thereafter, 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," Johnson added.Why it matters: Cummings, a highly polarizing figure in British politics, is widely viewed as the architect of the Brexit campaign and Johnson's most influential adviser. Allegations that he broke lockdown rules came as the number of confirmed coronavirus cases in the U.K. surpassed 250,000 and the death toll neared 37,000.Johnson's move to unambiguously back Cummings amid national outcry could prove to be a politically significant decision down the road.The big picture: Calls for Cummings to resign grew over the weekend among opposition leaders and even some Conservative MPs, who pointed out the hypocrisy of a top adviser breaking the stringent rules that his government had long stressed were mandatory.On Saturday, members of Johnson's Cabinet came out in support of Cummings on Twitter, calling it "justifiable" and "reasonable" for him to seek family help to take care of his young child while he and his wife potentially fell ill from the coronavirus.But later that day, the Mirror and Guardian broke a second story alleging that Cummings had been spotted in his parent's town of Durham on April 19 after recovering from the virus and being photographed in London days earlier.Another witness claims they saw Cummings in Barnard Castle, a popular English tourist destination, on April 12.What they're saying: "Yesterday the Mirror and Guardian wrote inaccurate stories about Mr Cummings," Downing Street said in a statement. "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."Steve Baker, the first Conservative MP to call for Cummings' resignation, said on the BBC: “Dominic is the inventor of these three-word slogans: 'Stay at Home,' 'Protect the NHS' and 'Save Lives.' ... The country can’t afford this nonsense, this pantomime, now. Dominic should go, and we should deal with the things that matter in people's lives.Roger Gale, another backbench Conservative, tweeted: "While as a father and as a grandfather I fully appreciate Mr Cummings’ desire to protect his child. There cannot be one law for the Prime Minister’s staff and another for everyone else. He has sent out completely the wrong message and his position is no longer tenable.""Is it one rule for you, Mr Cummings, and another rule for everybody else?"That was what @MinnieStephC4 asked Dominic Cummings after new reports claimed the Prime Minister's top aide broke lockdown rules for a second time. pic.twitter.com/iM3LRbIntY— Channel 4 News (@Channel4News) May 24, 2020 This story is developing. Please check back for updates.