Tory Brexit rebels risk putting Jeremy Corbyn in power, a prominent Eurosceptic warned as the fallout from Theresa May's first Commons defeat over Europe continued.
Backbench MP Nadine Dorries, who has said the 11 rebels should face deselection, compared the situation to wartime and claimed her colleagues had a duty to support the Prime Minister.
But ex-cabinet minister Ken Clarke said it was "idiotic" to call for a purge of Tory Europhiles and "absurd" to say the revolt was helping the Labour leader.
The former chancellor also said the current cabinet - which will discuss Brexit over the coming days - was "deeply divided on the details" about the future trade deal it wants with the EU.
"Now we need to get on to a sensible economic future, worked out by people who are prepared to read the brief and know something about trade, investment and business in the modern, globalised, economy," he said.
Ms Dorries hit out at Mr Clarke and his fellow rebels, telling the BBC's Sunday Politics the "real heroes" were Tories who had backed Remain but were now supporting the Government's Brexit plans.
She said the rebels were pursuing a tactic of supporting measures to "frustrate and delay Brexit".
Ms Dorries, who has voted against her leaders on a series of issues in the past, said the difference now was "we have a Marxist government knocking on the door".
She added: "We have got a very important job to do, we are in very dangerous times, we are in a situation that has not been seen like this since wartime. They had a responsibility and that responsibility was to support the Government."
Another rebel, Anna Soubry, used a Mail on Sunday article to claim the Tories "have our very own Blue Momentum" - a reference to the Corbyn-supporting group which has been blamed for targeting MPs opposed to the Labour leader.
"A tightly-knit and co-ordinated group of Conservatives, including some MPs, are working with non-party members to get their hard version of Brexit at any cost," she said. "They are using the same pernicious tactics as Corbyn's Momentum."
But Ms Dorries shot back: "I think most of what Anna Soubry says is quite often nonsense, I think that is too."
Responding to the deselection calls, Mr Clarke told Sunday Politics: "It is utterly idiotic if a few of our association members in various parts of the country start interpreting this as the start of some sort of purge of backbench members of conscience.
"Eurosceptics have been voting against the government for the last 30 years and no one on my side of the argument has ever gone round saying that they should be expelled from the party and sent to outer darkness."
Meanwhile Tory peers Baroness Altmann and Baroness Wheatcroft said they were "shocked at the vilification" aimed at the rebels and dismissed "hysterical" claims the revolt had helped Mr Corbyn.
"We are deeply disappointed that colleagues who have rarely if ever rebelled before but want the best for their country are being lambasted for standing up for their beliefs on this crucial issue," they said in an Observer article.