President Obama has appointed one of his top election fundraisers and a fellow Chicagoan to the plum diplomatic post of US Ambassador to London, despite having campaigned to end a culture of cronyism.

Louis Susman, 71, whose likely appointment was first reported by The Times in February, raised more than $500,000 for Mr Obama’s presidential campaign and inauguration and is a longtime Democratic donor.

Mr Susman, whose official title will be US Ambassador to the Court of St James’s, is a recently retired vice-chairman of Citigroup Corporate and Investment Banking. Citigroup has received $45 billion of federal “bailout” funds since last year’s financial crash.

He served as national finance chairman for John Kerry’s presidential bid in 2004, earning the nickname “the vacuum cleaner” for his ability to hoover up campaign cash. Former recipients of Mr Susman’s fundraising prowess included the failed presidential campaigns of Democrats Ted Kennedy, Dick Gephardt and Bill Bradley. In addition to raising hundreds of millions, he was also a member of the Democratic National Committee during the 1970s.

Born in St Louis, Missouri, into a family that owned an industrial cloth company, Mr Susman attended the University of Michigan and Law School at Washington University in St Louis. He later became a senior partner at an eminent St Louis law firm and a director of St Louis Cardinals baseball team. His most notable client while in St Louis was August Busch Jr, the Budweiser beer magnate .

Moving to Chicago in 1989, Mr Susman bought a $1.5 million home in the fashionable Gold Coast neighbourhood, overlooking Lake Michigan, where he still lives with his wife, Margie. The couple have two adult children, Sally and William. Margie Susman has served on the board of the Chicago Museum of Contemporary Art and is active in charities ranging from people with physical disabilities to lupus research.

The Susmans served together on the leadership committee of The American Ireland Fund, a worldwide network of people of Irish ancestry whose stated purpose is to raise money for “worthy causes in Ireland”.

Mr Susman will arrive in London as the embassy begins the move from its building in Grosvenor Square to new premises south of the Thames at Nine Elms. He will inherit an ongoing dispute between the US Embassy and the office of the London Mayor over the non-payment of the congestion charge.

Nearly £3 million of unpaid charges have been run up by US diplomats, and Boris Johnson, the Mayor, recently urged Mr Obama to make the embassy pay. The embassy considers the congestion charge to be a direct tax on its staff and therefore non-payable under international law.

Mr Obama announced a string of other diplomatic postings. He nominated Miguel H Diaz, a Cuban-American theology professor, to represent the US at the Vatican.

He also picked Tim Roemer, a former member of the 9/11 commission and an early supporter in Mr Obama’s presidential campaign — at a time when Hillary Clinton looked a prohibitive favourite — as Ambassador to India.

Patricia Butenis, a diplomat in Iraq, is being sent to Sri Lanka. She was previously ambassador to Bangladesh and has worked in Pakistan, El Salvador and India.

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