Jacob Rees-Mogg has accused a doctor of "fear-mongering" after he challenged the Commons Leader to say how many people he would accept could die as a result of a no-deal Brexit.
Dr David Nicholl, a consultant neurologist who was involved in the Operation Yellowhammer report into the impact of a no-deal Brexit on the NHS, called in to LBC's Ring Rees-Mogg show on Monday to ask what "mortality rate" he would accept if the UK crashed out of the EU without a deal.
After the clash, Dr Nicholl called Mr Rees-Mogg “a muppet” and challenged him to report him to the General Medical Council.
It comes as top Tories prepare to defy prime minister Boris Johnson by blocking a no-deal Brexit in the House of Commons as he reportedly plans an early general election.
Dr Nicholl called the show and asked: "Having been involved in writing the plans for mitigation and having whistle-blown because I felt they were unsafe, what level of mortality rate are you willing to accept in the light of a no-deal Brexit?"
Mr Rees-Mogg replied: "I don't think there's any reason to suppose that a no-deal Brexit should lead to a mortality rate.
"I think this is the worst excess of Project Fear and I'm surprised that a doctor in your position would be fear-mongering in this way on public radio."
Dr Nicholl told the prominent Brexiteer: "Can I remind you I wrote the plans of mitigation?"
But Mr Rees-Mogg replied: "Well you didn't write very good plans if you hadn't worked out how to mitigate, had you?
"It's fortunate they are being written by other people now who are serious about mitigating, rather than Remoaners."
Dr Nicholl said people could die because of potential problems with access to drugs and radioactive isotopes in the event of a no-deal Brexit.
Mr Rees-Mogg said there were "reserve plans to fly drugs in if necessary".
He said: "This is a major focus of government policy. I think it's deeply irresponsible, Dr Nicholl, of you to call in and try to spread fear across the country.
"I think it's typical of Remainer campaigners and you should be quite ashamed, I'm afraid."
Dr Nicholl, who drew up a risk register of epilepsy and neurology drugs for Operation Yellowhammer, said later: “If he has got doubts about my probity, I am more than happy to be referred to the GMC.
“I am not bothered about Jacob Rees-Mogg,” he told The Guardian. “I’m not going to take a single word of health lessons from a muppet like him. What does he know about epilepsy or neuropathic pain?”
“What I am worried about is my patients. To suggest I am wrong in what I say is defamatory.
“When, as I have done, I look people in the eye and say some of the drugs they are on might be in short supply and who are understandably worried, what he says about me is ridiculous.”