The Labour Party — on course to form the next government on current polling — is furious at the news and argued that such a significant diplomatic appointment should not be made by the Conservative prime minister this close to the election.

Sunak told journalists on a flight to Poland that it was “entirely normal, entirely keeping with precedent” to appoint an ambassador well ahead of their start date “because ambassadors-designate often go and acclimatize themselves and build relationships before they formally start,” he said.

However, he would not be drawn on whether Barrow was about to be appointed. “Those announcements are made in the usual way,” he said.

The U.K. is in need of a new ambassador to Washington when Karen Pierce steps down this year, after a four-year stint in the job.

Barrow has worked in the civil service for nearly 40 years and was previously the U.K.’s ambassador to the EU.

The prime minister also said Jenkins, his new national security adviser, had a “very distinguished career in the armed forces” and that it was the first time anyone with a military background had been appointed to the role since it was created in 2010.