Britain’s ambassador to Washington quit on Wednesday after days of stinging criticism from Donald Trump, leading to accusations that Boris Johnson, the favourite to be the next British prime minister, had “thrown him under the bus”. Memos from Kim Darroch in which he described the Trump administration as inept were leaked to a British Sunday newspaper, infuriating the US president, who launched a Twitter attack on both the envoy and outgoing British Prime Minister Theresa May, who had given Darroch her full support. As the spat between the two close allies intensified, Trump said he would no longer deal with the “very stupid” Darroch and called May “foolish”. Darroch said his position had become untenable, but supporters blamed Johnson, the former London mayor who could take over from May later this month, for refusing to back him. “Since the leak of official documents from this Embassy there has been a great deal of speculation surrounding my position and the duration of my remaining term as ambassador,” said Darroch, who was due to step down at the end of the year. “I want to put an end to that speculation. The current situation is making it impossible for me to carry out my role as I would like.” In his confidential memos dating from 2017 to the present, Darroch, 65, had said reports of in-fighting in the White House were “mostly true”, and last month described confusion within the administration over Trump’s decision to call off a military strike on Iran. ‘Clumsy And Inept’ “We don’t really believe this Administration is going to become substantially more normal; less dysfunctional; less unpredictable; less faction-riven; less diplomatically clumsy and inept,” Darroch wrote in one cable. It led to a scathing tirade from the US president. “The wacky Ambassador that the UK foisted upon the United States is not someone we are thrilled with, a very stupid guy,” he tweeted, describing Darroch as a “pompous fool”. Britain prides itself on its “special relationship” with its closest ally and Trump himself described it as “the greatest alliance the world has ever known” during a lavish state visit last month. That relationship is of particular importance to London now, as it hopes to strike a major trade deal with Washington as one of the upsides of leaving the European Union, a departure currently scheduled for Oct. 31. Darroch, a career diplomat who previously served as Britain’s envoy to the EU, had been accused by some Brexit supporters of being biased towards the bloc. Trump himself had previously suggested that Nigel Farage, now leader of Britain’s Brexit Party, would be a good choice as ambassador, irritating British officials. While May said the government did not share Darroch’s views of the Trump administration, she said British ambassadors should have the freedom to give frank assessments. “I have told him it is a matter of great regret that he has felt it necessary to leave his position as ambassador to Washington,” she told parliament. “The whole cabinet rightly gave its full support to Sir Kim on Tuesday.”