Keir Starmer has finally announced his new pick for British ambassador in Washington, months after being forced to sack Peter Mandelson over the Jeffrey Epstein scandal.

The PM has this evening appointed career diplomat Christian Turner as his new top dog in the US, at a crucial time for British-American relations.

Mr Turner has spent his life working in similar circles, currently as the British ambassador the United Nations since May.

He was previously political director at the Foreign Office, his old department spending months pushing for Sir Keir to pick an experienced hand to replace Lord Mandelson.

No 10 will now request Washington’s formal consent.

On the appointment, Prime Minister Sir Keir Starmer said: “The United Kingdom and United States have a very special relationship, and Christian’s extensive experience as an outstanding diplomat will support this uniquely close bond and ensure it continues to flourish.

“I warmly congratulate him as he starts his work to further build our strong economic and security ties and deliver for the British people.”

Foreign secretary Yvette Cooper said Mr Turner “brings exceptional diplomatic experience and deep understanding to this vital role”.

Mr Turner added: “I am honoured to be nominated to serve as the UK’s Ambassador to the USA. Our two countries share a historic partnership rooted in common values, shared security and deep economic ties.

“At a pivotal time for the transatlantic relationship, I look forward to working with President Trump’s administration, and leaders in Congress, business and society to strengthen that bond in the years ahead.”

The role has been vacant since September following the sacking of the Labour grandee over his relationship with notorious child abuser Jeffrey Epstein.

The final straw broke when US lawmakers published fresh email evidence of the pair’s relationship, revealing that Lord Mandelson had protested the New York financier’s innocence after his first conviction for child abuse.

His sacking sparked political turmoil for Sir Keir, with Tory leader Kemi Badenoch saying it showed him failing “yet another key test of leadership”.

He gave his full backing to a man unfit for office. This matters to you because the Prime Minister has been distracted from the serious national security and economic challenges this country is facing.

“This is a weak Prime Minister, who doesn’t have the courage to do the right thing at the right time.”

Mr Turner beat rivals including Nigel Casey, UK envoy to Russia; and the PM’s business adviser Varun Chandra, who helped negotiate a string of deals with the Trump administration including on pharmaceuticals.

However Sir Keir was pursuaded by the Foreign Office of the need for a more experienced hand given pressures on the UK-US relationship.

Earlier this week Donald Trump suspended a £31 billion technology deal signed with Sir Keir Starmer during the American President’s much lauded state visit to the United Kingdom earlier this year.

The “technology prosperity deal” was intended to build cooperation between the United States and the United Kingdom, with a focus on artificial intelligence (AI), quantum computing and nuclear energy.

Suspending the deal is reportedly intended to pile on the pressure on Sir Keir Starmer’s floundering government, in areas where Trump is said to be looking for more concessions. These include the Trump Administration’s plans for more agricultural exports into the UK, and for the UK to loosen its food safety standards.

Earlier this year a trade agreement in principle was agreed between the President and the UK Prime Mister, however the full text was not hashed out, despite a glossy photo-op by the Prime Minister, who posed with the signed tech deal in September.

A UK government spokesman said: “Our special relationship with the US remains strong and the UK is firmly committed to ensuring the tech prosperity deal delivers opportunity for hardworking people in both countries.”