Leading pro-Europe Tory Anna Soubry has threatened to quit the party and form a new political alliance because of Brexit.
The former minister has called on Prime Minister Theresa May to "stand up to" arch Brexiteers like Boris Johnson and Jacob Rees-Mogg and "slung 'em out".
She told BBC2's Newsnight: "If it comes to it, I am not going to stay in a party which has been taken over by the likes of Jacob Rees-Mogg and Boris Johnson.
"They are not proper Conservatives."
Ms Soubry added: "Unless Theresa stands up and sees off these people she is in real danger of losing huge swathes of not just the parliamentary party but the Conservative Party.
"And if that means leaving the party, form some new alliance, God knows I don't know.
"But we just simply cannot go on like this any longer.
"Something is going to have to give because if it doesn't not only will we get Jacob Rees-Mogg as our prime minister, we will get a devastating hard Brexit which will cause huge damage to our economy for generations to come.
"And I am not prepared to sit by any longer and put up with this nonsense."
Ms Soubry called for a re-evaluation of what the Tories represented, stating: "Labour's frontbench itself is ideological.
"My frontbench probably isn't but it is in hock to 35 hard ideological Brexiteers who are not Tories.
"They are not the Tory party I joined 40 years ago and it is about time Theresa stood up to them and slung 'em out.
"We have to get a Conservative Party which is what it has been for decades, the party I joined 40 years ago, proper, One Nation, centrist, small l socially liberal, fiscally sensible, economically sound Conservatives."