Tory and Labour MPs have defended the NHS after US presidential candidate Mitt Romney's running mate said "socialised" healthcare was detrimental to patients.
Paul Ryan said nationalised healthcare systems such as Britain's were slower to develop lifesaving drugs and had a damaging effect on the economy.
But Labour shadow health minister Jamie Reed hit back, saying Ryan's criticisms were a "lie" and that the NHS was one of the "defining achievements of Britain".
And Stephen Dorrell, a former Conservative health secretary, said he thought the vice presidential candidate appeared not to understand how the NHS worked and that it was not the "devil incarnate".
Ryan, who was unveiled by Romney on Saturday, is best known for the so-called "Ryan Budget" plan which would, among other things, cut funding for the Medicare and Medicaid programmes which provide healthcare for pensioners and those with low incomes .
He also wants to repeal the Affordable Care Act, President Obama's flagship health care law known as "Obamacare".
Writing in the Wall Street Journal in January 2009, the Wisconsin congressman singled out the NHS as an example of bad practice as Republican's battled to block Obama's health care reforms.
"Nationalising health care will be profoundly detrimental to the quality of American medicine," he wrote.
"In the name of cost control, the government would make private investment in medical innovation far riskier, and thus delay the development of potentially lifesaving treatments.
Ryan warned that Obama's plan would "put America on a glide path toward European-style socialism".
"We need only look to Great Britain and elsewhere to see the effects of socialised health care on the broader economy," he said.
"Once a large number of citizens get their health care from the state, it dramatically alters their attachment to government.
"Every time a tax cut is proposed, the guardians of the new medical-welfare state will argue that tax cuts would come at the expense of health care - an argument that would resonate with middle-class families entirely dependent on the government for access to doctors and hospitals."
Labour's Jamie Reed told The Huffington Post UK that there had been a "long tradition" of "misrepresenting and defaming Britain's National Health Service in US politics".
"It's a misguided tradition and in the wake of Obamacare, an increasingly mendacious one. The facts are that the NHS is one of the most effective and efficient healthcare systems anywhere in the world: it's a lie to claim otherwise," he said.
"It simply isn't true or credible to state that publicly funded healthcare delays the development of new medicines or other treatments and the NHS - as the Olympic opening ceremony again underlined - is one of the defining achievements of Britain and a cornerstone of British life and culture.
"It's benefits for the economy and every other part of British life have been incalculable.
"It seems that every time certain Republicans panic, they reach out to criticise the NHS. They should resist speaking about what they don't understand. In the words of David Bowie, 'this is not America.'"
At the height of the 2009 fight over Obama's health care reforms the NHS was dragged into the debate to such an extent that the Department for Health took the unusual step of issuing a rebuttal to some of the claims made by critics.
"People have been saying some untruths in the States," a spokesman for the DoH told the Associated Press at the time.
"There's been all these ridiculous claims made by the American health lobby about Obama's health care plan and they've used the NHS as an example. A lot of it has been untrue."
Ryan's comments about the NHS arguably have more significance now that he would be vice president should Mitt Romney beat Barack Obama in November.
Stephen Dorrell, who was Conservative health secretary under John Major in the mid-1990s, said that while he did not disagree "entirely" with Ryan's views, the congressman had not provided evidence to back up his claim that Europe was less innovative in medical research than the United States.
"The only basis on which he can go on to say that socialised healthcare inhibits developments of lifesaving treatments is if it can be shown lower pricing brought about by those pressures actually inhibits developments of new treatments," he said.
"And I don't think you can show that, I wouldn't say innovation is slower in Europe than in the US."
Dorrell, who is now the chair of the House of Commons health committee, told the Huffington Post UK that the vice presidential candidate, as well as British politicians, would have to accept that the European and American models were moving closer to one another.
"Ironically what is actually happening is although it is in the interests of American and European politicians to distance themselves from each other, what is happening is a convergence of policy," he said.
"The rising demand for healthcare is creating a tension between the desire to hold down taxes and desire to meet consumer demand for care.
"Both Europe and North America start from a position where there is a private sector and a state sector and the two are kept remarkably separate.
"Both systems are being driven in the direction of integrating the private sector and the tax supported sector because that is the only way of delivering socialised healthcare, that is, care based on need not ability to pay.
"They both are working out how to get onto common ground from very different starting potions, when both have an interest to demonstrate to their electorates the other system is the devil incarnate."
He also said Ryan's criticism of the NHS were misguided as he appeared not to understand how the system worked. Dorrell said that the whole direction of European health policy was to distinguish between entitlement and ownership.
He said the goal was to provide "socialised access but not to have nationalised supplies".
Dorrell also said Ryan's proposals to cut spending on healthcare while at the same time increasing spending on the military was "pretty bold", indicating it was perhaps politically unwise.
"It's a brave policy to take discretionary spending down and preserve military spending at the same time, but there is nothing wrong with ambition," he said.
Labour backbencher Katy Clark, who is on the left of the party, said for most people in Britain Ryan's characterisation of the NHS "would be quite bizarre".
"Historically if you look at the way the NHS has worked it has been very cost effective," she said.
She told HuffPost that it was no bad thing that the middle classes felt attached to state provided healthcare.
"What you have is mass buy-in to the state providing a public service, it does change the attitude of people in the middle classes towards the state when they have got a stake.
Clark added: "They use their power to drive the improvement in standards."