Keir Starmer has appointed the career diplomat Christian Turner as the new ambassador to Washington, government sources have confirmed.

Turner will be replacing Peter Mandelson who was forced to quit over his links to Jeffrey Epstein.

Turner, the ambassador to the United Nations, was previously political director at the Foreign Office and brokered a close relationship with the new Labour administration before he left for New York.

The Foreign Office is said to have pushed hard for an experienced diplomat to take the role, as well as someone experienced enough to handle the turmoil of Donald Trump’s administration.

Turner was chosen over the prime minister’s business adviser, Varun Chandra, who will take on an expanded role in Downing Street, and Nigel Casey, the ambassador to Russia.

The US ambassador role has been vacant since Mandelson was sacked in September for failing to disclose the extent of his ties with the child sex offender Epstein.

Mandelson was found to have urged the financier to “fight for early release” from jail in 2008 as he faced an 18-month sentence for procuring a child for prostitution and soliciting a prostitute.