British Minister of State for Europe and the Americas Alan Duncan resigned on Monday, the Foreign Office confirmed in a statement on Monday. According to the Telegraph, 11 more ministers are expected to follow in the next couple of days.
Chancellor of the Exchequer Philip Hammond announced yesterday that he will resign if Boris Johnson becomes the country's next prime minister, which is highly likely. Duncan is a known critic of Boris Johnson, especially in regards to his reaction to the leaks of statements made by London's ambassador to Washington, Kim Darroch. The Times political said that Duncan has "made clear he can't serve under a Boris Johnson premiership."
Justice Secretary David Gauke also said on Sunday he would quit if Johnson was elected to lead the government.