Kim Darroch called the US President “incompetent, “inept” and “insecure” in memos obtained by the Mail on Sunday. He also said the White House had become “uniquely dysfunctional” with Mr Trump as President, due to “vicious infighting and chaos”. He said: “We don’t really believe this administration is going to become substantially more normal; less dysfunctional; less unpredictable; less faction riven; less diplomatically clumsy and inept.”
Mr Trump has since told reporters: “The ambassador has not served the UK well, I can tell you that.
“We are not big fans of that man and he has not served the UK well.
“So I can understand it, and I can say things about him but I won’t bother.”
Mr Darroch also said the president had been “dazzled” by the pomp and ceremony of his state visit to the UK in June.
But his administration would remain self-interested and “this is still the land of America First”.
A formal inquiry is set to be held into the leak of the memos.
But officials have defended Mr Darroch’s style and said the White House can deal with “mischievous behaviour”.
Brexit Party leader Nigel Farage, who is also a close friend of Mr Trump, called for Mr Darroch to be sacked.
He said: “From the moment Trump was elected this man was the wrong person to be the British ambassador – a globalist in outlook, totally opposed to the Trump doctrine.
“The comments are wholly unsurprising but for him to speculate about Trump’s alleged involvement with Russia shows him to be totally unsuitable for the job and the sooner he is gone the better.”
Foreign Secretary Jeremy Hunt called Mr Darroch’s remarks “a personal view”.
He said: “It’s not the view of the British Government. It’s not my view.
“We continue to think that under President Trump the US administration is not just highly effective but the best possible friend of the United Kingdom on the international stage.”
A Foreign Office spokesman said: “The British public would expect our ambassadors to provide ministers with an honest, unvarnished assessment of the politics in their country.
“Their views are not necessarily the views of ministers or indeed the Government.
“But we pay them to be candid. Just as the US ambassador here will send back his reading of Westminster politics and personalities.
“Of course we would expect such advice to be handled by ministers and civil servants in the right way, and it’s important that our ambassadors can offer their advice and for it remain confidential.
“Our team in Washington have strong relations with the White House and no doubt. These will withstand such mischievous behaviour.”