Health Secretary Jeremy Hunt has launched a fresh attack on Professor Stephen Hawking for suggesting the "direction of change" in the NHS is towards a US-style insurance system.
It came around 17 hours after Mr Hunt rejected the world renowned scientist's allegation that he "abused" scientific research to justify the creation of a seven-day NHS and the imposition of a new junior doctors' contract.
The war of words broke out on Friday when Prof Hawking, a lifelong Labour supporter, accused the Health Secretary of "cherry-picking" favourable evidence while suppressing contradictory research in order to suit his argument.
The 75-year-old, who was diagnosed with motor neurone disease in 1962 and said he "would not be here today if it were not for the service", also suggested the NHS was at risk of privatisation under the Tories.
His comments were supported by Labour leader Jeremy Corbyn and former Liberal Democrat leader Tim Farron.
But on Twitter on Saturday, Mr Hunt hit back.
"Most pernicious falsehood from Stephen Hawking is idea govt wants US-style insurance system. Is it 2 much to ask him to look at evidence?" the Health Secretary said.
"NHS under Cons has seen more money, more docs and more nurses than ever in history.Those with private med insurance DOWN 9.4% since 2009!"
On privatisation, Prof Hawking said the NHS was being subjected to competing forces, with the public who want a taxpayer-funded free service on one side and multinational corporations on the other.
He wrote: "In the US, where they are dominant in the healthcare system, these corporations make enormous profits, healthcare is not universal, and it is hugely more expensive for the outcomes patients receive than in the UK.
"We see the balance of power in the UK is with private healthcare companies, and the direction of change is towards a US-style insurance system."
It comes after the pair found themselves embroiled in a row over the so-called "weekend effect".
The Health Secretary used his drive to create a seven-day NHS as one of the main reasons for reforming junior doctors' contracts - which led to the biggest walkout of doctors in NHS history.
Mr Hunt has cited studies showing higher death rates at weekends when setting out his argument for a seven-day health service.
But Prof Hawking, who is director of research at the Centre for Theoretical Cosmology at the University of Cambridge, accused him of suppressing contradictory research to suit his argument.
He wrote: "Hunt had cherry-picked research to justify his argument. For a scientist, cherry-picking evidence is unacceptable.
"When public figures abuse scientific argument, citing some studies but suppressing others to justify policies they want to implement for other reasons, it debases scientific culture.
"One consequence of this sort of behaviour is that it leads ordinary people to not trust science at a time when scientific research and progress are more important than ever."
Mr Corbyn backed Prof Hawking, telling broadcasters in north Wales: "If Stephen Hawking is saying that our NHS is under threat and in danger and in crisis then I think we need to listen very, very carefully with what he has to say.
"I admire Stephen and I agree absolutely with what he said."
Mr Farron said: "A renowned scientist such as Stephen Hawking questioning your evidence might normally be cause to think again, but sadly it looks as though Jeremy Hunt has joined the chorus of those who have had enough of experts."