Theresa May must “make a decision” on trade following Donald Trump’s scathing comments about her Brexit plan, a Republican spokesperson has warned.
Trump has warned May her Brexit plan could "kill" any UK-US trade deal because Britain would remain so closely aligned to the European Union.
The US president said he would have done the Brexit negotiations "much differently" and claimed the Prime Minister did not listen to his advice, in an interview with The Sun.
“It adds much more pressure on her, because it has to make a decision,” Sarah Elliot, chair of Republicans Overseas UK, told Julia Hartley-Brewer.
“I think she is in a corner and either she has to double down on the White Paper and say, ‘no, this is the best deal’, or she listens to what he has to say and says, ‘the US is the largest single investor in a UK, a trillion dollars worth of goods and services already come between the two countries, let’s make a deal, Mr President’.”
Statistics show that in 2016, the UK exported £100 billion worth of goods to the US and imported £66 billion.
Trade deal with US ‘probably won’t be made’
Watch Sarah Elliot talking to Julia Hartley-Brewer above
In a Sun interview released while Mr Trump and First Lady Melania were being entertained by the Prime Minister at Blenheim Palace, the president said: "If they do a deal like that, we would be dealing with the European Union instead of dealing with the UK, so it will probably kill the deal.
"If they do that, then their trade deal with the US will probably not be made."
The comments, following on from the morning press conference, will be a cause of great concern for May.
She had used the Blenheim black tie dinner with political and business leaders to press Mr Trump on the benefits of a free trade deal after Brexit.
Addressing the 100-strong group the Prime Minister said there was an "unprecedented" opportunity to do a deal that boosted jobs and growth in both countries.
US has ‘difficulty’ with EU
But Mr Trump appeared to link Brexit to the current trade dispute between the US and EU over steel and aluminium.
He told The Sun May's plan would affect trade "unfortunately in a negative way". He added: "We have enough difficulty with the European Union.
"We are cracking down right now on the European Union because they have not treated the United States fairly on trading.
"No, if they do that I would say that that would probably end a major trade relationship with the United States."
Boris Johnson ‘would make a good PM’
He also said that Boris Johnson would be a “great Prime Minister”, adding: "I was very saddened to see he was leaving government and I hope he goes back in at some point.
"I think he is a great representative for your country.
"I am just saying I think he would be a great Prime Minister. I think he's got what it takes."
The pair have not always seen eye-to-eye, however.
Trump is due to meet May at Chequers later today.