Billionaire investment banker Warren Stephens has been officially confirmed as the next US Ambassador to Britain, after receiving backing from the U.S. Senate in a 59 to 39 vote.

Mr Stephens, who serves as chairman, president and CEO of Stephens Inc., a major financial services firm based in Little Rock, Arkansas, was nominated by President Donald Trump.

A longtime Republican donor, Stephens has poured millions of dollars into supporting GOP candidates — including Trump’s campaigns and his 2025 inauguration fund.

The appointment is likely to be seen as a strengthening of ties between Washington and London, with Downing Street expected to formally welcome the new ambassador in the coming days.

U.S. presidents have long appointed high-profile donors to the coveted ambassadorial role in London. During Donald Trump’s first term, the post was held by Woody Johnson, billionaire owner of the New York Jets NFL team.

When the White House initially announced it was nominating Stephens, Trump praised his allies credentials in his Truth Social statement: "Over the last 38 years, while serving as the President, Chairman, and CEO of his company, Stephens Inc., Warren has built a wonderful financial services firm, while selflessly giving back to his community as a philanthropist."

He added, “I am thrilled that he will now have that opportunity as the top diplomat, representing the USA to one of America’s most cherished and beloved allies.”

Despite the high praise, Stephens has not always been a supporter of Trump. When Trump first ran for president in 2016, $4m (£3.1m) was donated by the investment banker to rival political groups, reported the BBC. However, once Trump gained power, Stephens threw his support behind him.

At the time of his nomination as London ambassador in December Stephens said, "I have expressed to President Trump that I would be extremely proud to serve our country and his administration, working to implement the President’s agenda and further strengthen the long-standing alliance between the United States and the United Kingdom."

Stephens now steps into the role at a pivotal moment in UK-US relations, as Prime Minister Keir Starmer’s government works to reset ties with the European Union following the aftermath of Brexit, which saw Britain formally leave the EU in 2020.

The Starmer administration is also pushing for a revamped economic agreement with Washington, aiming to ease tariffs imposed on imported goods during Trump’s previous presidency — part of broader efforts to stabilise trade and security partnerships.