James Roscoe, Britain’s second most senior diplomat in Washington, has abruptly left his post, the Foreign Office confirmed. Roscoe had served as deputy head of mission at the British embassy since 2022 and briefly acted as interim ambassador after the sacking of Peter Mandelson. No reason was given for his sudden departure.
His exit comes amid an investigation into the leak of discussions at a UK national security council meeting. The meeting reportedly involved a proposal by Prime Minister Keir Starmer to allow the US to use British bases for defensive strikes against Iran, which was opposed by several senior cabinet members. The leak, considered a serious breach of the Official Secrets Act, prompted an investigation ordered by Justice Secretary David Lammy.
Roscoe played a key role in diplomatic events, including Donald Trump’s state visit to the UK in September 2025 and King Charles’s state visit to the US for the 250th anniversary of American independence. Before his Washington posting, he served as UK ambassador to the UN and as communications chief to Queen Elizabeth II from 2013 to 2016.
His earlier career included roles as chief press officer in Downing Street for Tony Blair and Gordon Brown, and diplomatic postings in Sierra Leone and Iraq. Roscoe was reportedly seen as focused on operational aspects of UK-US relations rather than being a figurehead.
