Dominic Grieve has promised to battle Boris Johnson should he attempt to remove him from the Conservative Party for voting against the government.
The Tory MP told talkRADIO’s Julia Hartley-Brewer party loyalty and career considerations “must take the backseat” to the future of Britain.
“I’ve been a Conservative member for about 48 years now. I’ve been an MP for 22. I’ve always seen myself as an out-and-out Conservative and will remain so,” he said.
“If I can’t stand as a Conservative candidate because the Prime Minister has decided in his wisdom that he is going to turn into a ruthless ideologue against people who disagree with him I will fight him by whatever other means I can in order to try to maintain true conservatism.”
On Monday the Prime Minister warned rebellious Tory MPs they risked being barred from standing for the party at a future election if they fail to support the government.
Dominic Raab told talkRADIO MPs must not undermine the chance of getting a deal with the EU by voting for a “ludicrous” piece of legislation set to be put forward by Labour MP Hilary Benn to block a no-deal Brexit.
Mr Grieve has been a constant thorn in the Johnson government’s side over Brexit, and said the Conservative Party would tear itself apart if it continued treating its own members with such “ruthlessness”.
He has pledged to defy the Prime Minister and support Mr Benn’s Bill to extend the Brexit deadline, although he admitted it was a “stop-gap measure”.
“I’m the first to accept that delaying yet again the Brexit date is a far from ideal solution,” he said.
“We need to focus on how we get out of the current political crisis, try to maintain the unity of the United Kingdom which is now under great threat as a consequence of it, and bring this to some form of resolution.”
He added: “It’s better to do a stop-gap measure and prevent disaster than to do nothing at all.”