This is awkward for Downing Street to say the least. The person chosen by the British government to be the keystone in the most important of bilateral relationships is, according to one of the incoming president's close aides, a "absolute moron".

Chris LaCivita is a central character in Trump's orbit.

He managed Trump's election victory with incoming White House chief of staff Susie Wiles. He's inner circle.

The words were clearly designed to stir things up. But why?

Inside the embassy Lord Mandelson is soon supposed to move into, they've been under the impression that relations with the incoming administration were good. There's been hard work by current ambassador Karen Pierce and her team to cultivate the relationship.

That's presumably why LaCivita calls Pierce a "professional universally respected ambo" in the same breath as the Mandelson broadside.

My calls today to Team Trump and to LaCivita for clarity have curiously gone unanswered. You can bet that similar attempts were made by senior British officials in Washington - to do some Mandelson-grade spinning and insist his comments were historical and not representative of his view now.

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The key question is the extent to which LaCivita is an outlier in thinking Mandelson is an "absolute moron" or whether he was informally speaking for Trump too.

Either this will blow over or it will fester. If it's the latter, then the Mandelson appointment could become a real problem notwithstanding the real assets he'd bring to the job.

The bigger question is why Number 10 didn't spot Mandelson's podcast comments and pre-empt all this. They could at least then have been prepared. A shambles in Downing Street?

(c) Sky News 2024: Trump aide's Mandelson jibe was clearly designed to stir things up - but why?