Sadiq Khan has shown interest in backing Mike Bloomberg and Pete Buttigieg in the ongoing US Democratic primary.

In an interview with Politico, the Labour mayor of London said it was important that the US Democrats “pick someone who can beat Trump”.

He went on to say that he thought Bloomberg and Buttigieg were “interesting”, and appeared to rule out their more left-wing rivals in the contest.

Asked about the ongoing primary, Khan said: “The key thing for the Democrats is to pick someone who can beat Trump… I think Mike Bloomberg is interesting. He clearly gets under Trump’s skin.

“If it’s Bloomberg vs Trump it will be a really interesting campaign; two New Yorkers. One of whom is a successful self-made billionaire. The other one less successful, lost his dad’s money, doing less well.”

The mayor added: “I think Buttigieg is interesting. I’d query whether Sanders or Warren or Biden would do as well. But let’s wait and see.”

Buttigieg is the youngest candidate in the race at the age of 38. He is the mayor of South Bend, Indiana and would be the first openly gay President if successful.

‘Mayor Pete’, as he is often known, was a late addition to the race, announcing his candidacy in April 2019. He previously stood to be the chairman of the Democratic National Committee.

He has dismissed plans to overhaul to US healthcare with a government-run system put forward by Sanders, and has instead suggested one that would preserve private insurance schemes.

78-year-old Bloomberg is the former Republican mayor of New York who endorsed the Republican President George W Bush in 2004 before leaving the GOP in 2007.

The ex-mayor only registered as a Democratic in October 2018, shortly before launching his bid to become the Democratic candidate for President.

Bloomberg is a billionaire and has used more than $500m of his personal fortune on television and online advertising in the campaign so far.