If anyone can secure an unlikely American trade deal, it is Peter Mandelson

Peter Mandelson has more lives than a cat. Sacked twice as a cabinet minister by Tony Blair, he then had a third career as a European trade commissioner. His fourth incarnation was the most surprising, when he was brought back into government as business secretary by his arch-enemy Gordon Brown.

Brown made him a minister via the House of Lords, elevating the “Prince of Darkness”, a nickname earned in his early role as New Labour spin doctor, to the “Lord of Darkness”. Eight months later, he was made first secretary of state as well, and was in effect Brown’s deputy prime minister, until the end of that government 14 years ago.

Now, at the age of 70, he is on the edge of a fifth big job. He is said to have made a “credible pitch” to be the British ambassador to Washington, according to The Daily Telegraph. My sources are not denying it, although they point out that he is also in the running to be chancellor of the University of Oxford, to replace Chris Patten.

Neither job is assured. The Oxford post depends on a vote – to be held online for the first time – of the university’s 250,000 graduates. That vote will be held at the end of October or start of November, which is when the US presidential election will be.

I am told that, although the appointment of a new ambassador to the US is “not remotely on the prime minister’s radar”, Keir Starmer has already taken two decisions.

One is that he agrees with the suggestion made by David Lammy, the foreign secretary, that the next ambassador should be a political figure rather than a civil servant. That means that the leading candidates are Peter Mandelson, David Miliband and Catherine Ashton.

Starmer’s other decision is that he will determine his choice after the US elections, so that he knows which president the new ambassador will be dealing with.

Mandelson, Miliband and Ashton are all highly qualified. Miliband was foreign secretary in the last Labour government and runs the International Rescue Committee aid charity based in New York. Ashton was Mandelson’s successor as EU trade commissioner before serving as the EU’s first high representative for foreign affairs.

I suspect, though, that Mandelson, if he doesn’t get the Oxford job, has the edge in the race for 3100 Massachusetts Avenue, the ambassador’s Lutyens mansion in Washington DC. The Telegraph’s source was impressed with Mandelson’s reputation for mixing with plutocrats: “He’s a person of political weight and substance. He knows power, he understands money, has no problem whatsoever rubbing shoulders with the 1 per cent.”

But more significant is Mandelson’s record as EU trade commissioner. The last big attempt to liberalise world trade in 2008 foundered on the refusal of the US and India to make the concessions needed for a deal, but Mandelson won praise from all quarters for his attempts to bridge the gap. George W Bush, coming to the end of his time as president, called him “Silver Tongue”.

The reason for making Mandelson ambassador is not because he rubs shoulders with the rich, but because, if there is anyone who could deliver that holy grail of post-Brexit politics, a US-UK trade deal, it is he. Such a prize could not be won by the bluff and boosterism of Boris Johnson, however much Donald Trump was flattered by him. Any deal at all – and it would have to be a timid and limited treaty – will happen only if interests are aligned and skilful negotiators want to make it work on both sides.

It makes sense to wait to see whether the Starmer government will be dealing with a second Trump or a first Harris administration, and the pitch for a trade deal would be rather different, depending on which president the ambassador is pitching to.

In defending himself against the charge of cronyism in the Downing Street garden on Tuesday, Starmer misspoke slightly, saying he wanted “the best people for the best jobs”.

This is a case where, whether it is President Trump or President Harris, a big political figure with deep experience of trade negotiations, such as Peter Mandelson, would be the best person – and Britain’s representative in Washington is certainly one of the best jobs.