Conservative MP Nick Herbert said Boris Johnson has made a “big mistake” by failing to rule out suspending Parliament in order to deliver Brexit.
He told talkRADIO’s Alastair Stewart it was the “most foolish idea” he has heard in his 14 years as an MP.
“The idea that you try and get your way because you’re concerned that Parliament is going to vote in a particular way, simply by refusing to allow Parliament to vote by suspending it is extraordinary,” he said.
“This would be a step too far. You can’t just simply sweep aside Parliament because they happen to get in your way. That is to start to behave like an autocrat.”
Mr Johnson has refused to rule out suspending Parliament to prevent MPs voting against a no-deal Brexit.
Should he win the leadership race he could announce a Queen’s Speech for the start of November.
Parliament is traditionally closed for up to two weeks in the lead-up to the event, blocking a last-gasp Brexit vote.
Mr Herbert said it could produce the worst constitutional crisis of the Queen’s reign.
“Firstly, that really would be undemocratic, secondly it would draw the Queen straight into politics because there would be almost certainly - as Rory Stewart has already suggested - attempts to set-up a Parliament somewhere else,” he said.
“The Queen would be put in an extraordinarily difficult position by this. I think it’s a really unwise idea.”
Boris Johnson supporter Andrea Leadsom told talkRADIO she does not believe suspending Parliament would be the right thing to do.
“I just want to be very clear Boris hasn’t said he’s going to prorogue Parliament he’s just refused to rule out anything, which is quite right for somebody who is standing for the leadership of our party and our country,” he said.
“You don’t want to be pinning yourself down and shutting doors.”
She added: “It just depends on the circumstances but I certainly don’t think proroguing specifically for the purpose of avoiding scrutiny would be something that any Prime Minister would contemplate.”