Veteran Labour politician Peter Mandelson set to be named UK ambassador to the US

LONDON — Veteran U.K. Labour Party politician Peter Mandelson will be Britain's next ambassador to Washington, people familiar with the decision said Thursday.

Mandelson, who served in senior posts in the governments of Tony Blair and Gordon Brown, is expected to take up his job early next year. The announcement is expected to be made on Friday.

The current ambassador, Karen Pierce, is likely to remain in her post until after President-elect Donald Trump's inauguration on Jan. 20.

The news of Mandelson's appointment was first reported by The Times of London newspaper. It was confirmed by two people familiar with the decision, who spoke on condition of anonymity because it has not been formally announced.

Mandelson had been considered a front-runner for the job, considered Britain's most important diplomatic post - even more so with the protectionist Trump returning to office.

Mandelson served in government from 1997 to 2001 and again from 2008 to 2010, and in between was Britain's European Commissioner for trade. His trade expertise is likely to prove vital in dealing with the Trump administration, which has threatened to impose tariffs on almost all imported goods.

In November, the he told the BBC that he would be “very interested” in giving advice on trade to whoever got the job.

It is rare for politicians to be appointed as U.K. ambassadors — the jobs usually go to career diplomats.