Donald Trump’s claim that health care will be included in any future UK-US trade deal has been met by a furious backlash of opposition with political figures from Left and Right insisting Britain’s NHS “is not for sale”.

The President made his controversial remark during a joint press conference with Theresa May in the Foreign Office.

Amid the imperial grandeur of the Durbar Court, Mr Trump talked up the possibility of a UK-US deal and explained: "Our nations have more than 1 trillion dollars invested in each other's economics...As the UK makes preparations to exit the EU, the US is committed to a phenomenal trade deal between the US and the UK.

"There is tremendous potential in that trade deal; I say probably two and even three times what we're doing right now."

But when he was asked about the highly contentious issue of the tax-payer funded NHS being part of any such deal, the President declared: “When you're dealing in trade everything is on the table; so, NHS or anything else, a lot more than that, but everything will be on the table. Absolutely."

The Prime Minster was quick to interject, adding: "But the point in making trade deals is of course that both sides negotiate and come to an agreement about what should or should not be in that trade deal for the future."

Nonetheless, Mr Trump’s remarks caused widespread consternation; one fear is that if the NHS were part of a trade deal, it could lead to higher prices for drugs supplied by American companies.

Contenders in the Tory Party race to succeed Mrs May quickly moved to distance themselves from Mr Trump's call.

Matt Hancock, the UK Health Secretary, tweeted: “Dear Mr President. The NHS isn't on the table in trade talks and never will be. Not on my watch."

Dominic Raab, the former Brexit Minister, also insisted the NHS was “not for sale" and would not be if he were in No 10 while fellow contender Rory Stewart, the International Development Secretary, said he would not be "offering up" the NHS in any trade deal.

Jeremy Corbyn told an anti-Trump protest in Whitehall that he would not allow Brexit to open up “our precious wonderful NHS to private American companies to come in and take it over”.

The Labour leader said Tory leadership contenders as well as Nigel Farage, the Brexit Party leader, “all need to understand: our NHS is not for sale".

Sir Ed Davey, the Liberal Democrat leadership hopeful, said the sight of Mr Trump standing alongside a weakened prime minister repeating demands that the NHS should be up for negotiation in future trade talks was a “national embarrassment”.

He added: "I challenge all Tory leadership candidates to stand up to Trump’s demands, and firmly rule out our health service being on the table in any future trade deal talks."

Sara Gorton, head of health at the Unison union, said: "The Government shouldn't stoop to allowing the NHS to be used as a bargaining chip."

Rehana Azam, the GMB union's National Secretary, said Mr Trump was "just waiting to get his hands on our NHS" and "there's a very real danger Conservatives will just hand it over to him in a trade deal".

Chaand Nagpaul, Chairman of the British Medical Association Council, stressed: "We have an unequivocal message for the next Conservative leader and future prime minister: profit should never take priority over the protection of the health service and the healthcare of citizens."