A high-flying British diplomat in Washington has abruptly left his post.No explanation has yet officially been given for the departure of James Roscoe, who stood in as interim ambassador after Lord Peter Mandelson was sacked and had served as deputy head of mission at the British Embassy since 2022.He was reportedly among those tipped for the top diplomatic role after the removal of Lord Mandelson over his links to paedophile financier Jeffrey Epstein, though the plum posting ultimately went to Sir Christian Turner.As charge d’affaires to the US, Mr Roscoe played a key role in Donald Trump’s state visit to the UK last September.James Roscoe during Donald Trump’s state visit to the UK last September (Getty)More recently, as second in command at the embassy, he was involved in the King’s recent US state visit to mark the 250th anniversary of American independence.Before moving to Washington, he was the UK ambassador to the United Nations and previously served as communications chief to the late Queen Elizabeth II.He had also been chief press officer in Downing Street for prime ministers Tony Blair and Gordon Brown.Mr Roscoe’s earlier diplomatic postings included the UN, Sierra Leone and Iraq.In a brief statement, a Foreign Office spokesperson said: “James Roscoe has left his post.”