Mr Farage scored a huge political coup in becoming the first British politician to meet Mr Trump after his election victory, and said he was ready to play a "constructive" role in fostering close UK relations with the new regime at the White House.

But Mrs May's official spokeswoman pointed out that the Prime Minister has already had a phone conversation with Mr Trump, in which he invited her to visit Washington at the earliest opportunity and voiced his hopes of striking up a relationship comparable to that between Ronald Reagan and Margaret Thatcher.

"The president-elect talked about enjoying the same relationship Reagan and Thatcher did," said the spokeswoman. "I don't remember there being any third person in that relationship."

In response, Mr Farage told LBC radio: "It just amazes me that those ghastly little apparatchiks that work in Downing Street put out statements like this. It just goes to show they are not really interested in the country or the national interest, they are more concerned about petty party politics and trying to keep me out of everything.

"If you think of America in terms of a business and think of them as a client we want to do business with. What would you do? You would use the person who has the connections. Nobody in this administration in the UK has any connections with the Trump team at all, and yet they are prepared on behalf of the country to cut off their noses to spite their faces."

Mr Farage, who spent around an hour with the president-elect in his Trump Tower home in New York, said he had only gone to the US to meet "old friends" in the politician's team and did not expect to meet Mr Trump himself.

Mrs May herself last year described his remarks on Muslims as "divisive, unhelpful and wrong", while Foreign Secretary Boris Johnson said they made him "unfit" to be president.

Today, when asked about Mr Trump's victory, Boris Johnson said: "I think there is a lot to be positive about and it is very important not to prejudge the president-elect or his administration.

"It's only a few days since the election has taken place. I think we all need to wait and see what they come up with. But I think we should regard it as a moment for opportunity.

"Donald Trump is a dealmaker and I think that could be a good thing for Britain, but it could also be a good thing for Europe and that I think is what we need to focus on today."