James Roscoe, Britain's second most senior diplomat in Washington, has abruptly left his post. Roscoe had served as deputy head of mission at the British embassy since 2022 and stood in as interim ambassador after the sacking of Peter Mandelson. The UK government gave no reason for his sudden departure.
Roscoe's exit comes amid an investigation into the leak of discussions at a meeting of the UK's national security council. The leak reportedly involved cabinet splits over allowing the US to use British bases for strikes against Iran. Justice Secretary David Lammy ordered the investigation after The Spectator reported details of the meeting, which were later picked up by other media outlets.
As chargé d'affaires to the US, Roscoe played a key role in Donald Trump's state visit to the UK in September 2025. He was also involved in King Charles's state visit to the US to mark the 250th anniversary of American independence. Before moving to Washington, Roscoe served as UK ambassador to the UN and as communications chief to Queen Elizabeth II from 2013 to 2016.
Roscoe had also been chief press officer in Downing Street for Prime Ministers Tony Blair and Gordon Brown. His earlier diplomatic postings included Sierra Leone and Iraq. He was reported to have seen himself as being on the operational side of 'cleaning up the mess' in terms of relations with the White House.
