Jacob Rees-Mogg has been slammed by MPs for comparing a pro-Remain doctor to the discredited Andrew Wakefield, who is widely blamed for the MMR jab scare.
On Monday, David Nicholl, a consultant neurologist with Sandwell and West Birmingham Hospitals NHS Trust, called an LBC phone-in show and asked the leader of the Commons what mortality rate he would accept if the UK were to leave the EU without a deal.
The doctor had been involved in writing plans for mitigation and said he was forced to turn to whistle-blowing because he believed the proposals were unsafe.

On Thursday, Mr Rees-Mogg compared Dr Nicholl to Dr Wakefield during a Commons business statement.
In 1998, Dr Wakefield's discredited research linking autism and the measles, mumps and rubella vaccine prompted many parents to stop their children being immunised.
The North Somerset MP's speech was one of the driving forces behind the Conservative Party losing its majority when MP Phillip Lee crossed the floor to join the Liberal Democrats.
Mr Lee said the comments ignored the available evidence and were disrespectful to a member of his profession. He cited Mr Rees-Mogg's speech as the straw that broke the camel's back.
Mr Rees-Mogg told MPs: "Preparations are in place and they are being done with remarkable efficiency. But yes, a lot of Remainers wish to make our skins crawl.
"What he had to say, I will repeat it, is as irresponsible as Dr Wakefield in threatening that people will die because we leave the European Union. What level of irresponsibility was that?
Brexit
During the Commons business statement, Bristol West MP Thangam Debbonaire called on Mr Rees-Mogg to apologise for his remarks, but he insisted it was "scaremongering" to suggest people may die as a result of Brexit.
He said: "I'll reiterate it because I think this doctor's behaviour was disgraceful, and to scaremonger and to say that people are going to die because of Brexit is thoroughly irresponsible and unbefitting to his role."
SNP MP Carol Monaghan (Glasgow North West) said: "Can you confirm if it is Government tactic to cause reputational damage to experts such as Dr David Nicholl who dare to challenge the Government or indeed raise legitimate concerns about the impact of no-deal?"
Mr Rees-Mogg replied: "Frankly, I think when people start saying people are going to die because of Brexit their reputations are destroyed by themselves."
British Medical Association council chairman Dr Chaand Nagpaul hit out at the Tory MP's comments.
He said: "Jacob Rees-Mogg's latest insult about Dr David Nicholl is utterly disgraceful and totally irresponsible.
"Highly experienced doctors like David Nicholl who decide to speak out about risks to life and patient care should be supported and listened to, not attacked and derided by those who hold positions of responsibility.
"This unwarranted attack is particularly galling as Mr Rees-Mogg belongs to the same Government that called upon Dr Nicholl's expertise to help draft medical opinion for Operation Yellowhammer and who also wrote the mitigations for the event of a no-deal."
Dr Nicholl has been contacted for comment.
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