Donald Trump weighed into Britain’s domestic political turmoil by backing the pro-Brexit Boris Johnson to succeed Theresa May as prime minister, in a breach of convention on the eve of the president’s state visit to the U.K.Trump insisted he wasn’t giving a full endorsement of any one of the 12 candidates to become leader of Britain’s ruling Conservative party but said Johnson “would be excellent” and would do a ‘very good job’ running the country.“I like him,” Trump said in an interview with the Sun, the U.K.’s best-selling newspaper, which is owned by Rupert Murdoch’s News Corp. “I have always liked him. I don’t know that he is going to be chosen, but I think he is a very good guy, a very talented person,” Trump said.The president’s intervention -- before banqueting with Queen Elizabeth II at Buckingham Palace -- upends the usual diplomatic rules against commenting on allies’ internal political contests. It is potentially embarrassing for May for the president to be speculating in public about who will replace her just a few days before she welcomes him to London, where the pair will hold talks.An endorsement from Trump could also cut both ways. He’s not a popular figure in the U.K. and will be met with thousands of protesters when he arrives in London. Whoever becomes Tory leader might decide not to use Trump’s endorsement to win votes in a British general election campaign.In the Sun interview, Trump also praised Johnson’s rival, the Foreign Secretary Jeremy Hunt, while he was cooler on Michael Gove, another candidate for the Tory leadership who has criticized U.S. policy on Iran.May will step down on June 7 after repeatedly failing to get Parliament’s backing for the deal she negotiated to exit the European Union. The election to choose a successor as Tory party leader is due to begin formally on June 10.Trump created a stir last July when he said Johnson would make a great prime minister, shortly after the former London mayor quit as foreign secretary in protest against May’s proposed Brexit deal.In his interview in Saturday’s edition of the British tabloid, the president said that while he liked Johnson -- and the fact “he has been very positive about me” -- his words shouldn’t be construed as a full endorsement.“Other people have asked me for an endorsement, too,” Trump said. He added that he believed his backing would “help anybody,” and that he also was a fan of Hunt and his plan to increase defense spending. Trump said he hadn’t been approached by Gove, the environment secretary, who is also seeking to lead the Tories and has been critical of U.S. policy on Iran.Trump’s team are keen for the U.K. to have a clean break with EU trade rules and establish a sweeping free trade deal with the U.S. That fits with Johnson’s vision for Brexit.Leadership hopeful and Home Secretary Sajid Javid joined rivals including Johnson in backing a departure from the EU without any deal at all, if Parliament hasn’t backed one by Oct. 31, the latest deadline, the Conservative-leaning Telegraph newspaper reported on Saturday, citing allies of Javid’s.At the last asking, a majority of lawmakers didn’t support a no-deal Brexit, even if they couldn’t rally behind May’s compromise either. Bridging that gap will be the next leader’s central challenge.When he arrives on Monday, the U.S. President is expected to meet with the Queen at Buckingham Palace as well as Prince William, the Duke of Cambridge, his wife, Kate, the Duchess of Cambridge, and Prince Harry, the Duke of Sussex. Yet the forthcoming royal reception didn’t stop the president from criticizing Harry’s wife, Meghan, for calling him “misogynistic” and “divisive” during the 2016 presidential campaign.“What can I say? I didn’t know that she was nasty,” Trump said in the interview with the Sun, adding that “she will be very good” as a member of the royal family and that he hoped she succeeded in the role.Nigel Farage, the leader of the newly formed Brexit Party, told the U.K.’s Daily Express newspaper that May’s office had banned him from meeting Trump. The two share an anti-globalist stance, a populist turn of phrase and recent electoral success, and have championed each other. The Brexit Party was the U.K.’s strongest party in the recent European Parliament elections.