Foreign Secretary Jeremy Hunt has warned the Tories will be “annihilated” if they fight a general election before delivering Brexit.
Launching his bid to be next Conservative leader and Prime Minister, Mr Hunt won the backing of prominent Brexiteer Defence Secretary Penny Mordaunt.
Mr Hunt said he was prepared to leave the EU without a deal, but signalled he could extend Brexit beyond October 31 if an agreement was in sight.
He said: “Without a deal, any Prime Minister who promised to leave by a certain date would have to call a general election to change the parliamentary arithmetic.
“And that is an election we would lose badly.
“If we fight an election before delivering Brexit we will be annihilated.
“Squeezed by the Brexit Party on the right and the Lib Dems on the left. We will simply allow Labour through the middle.
“And, if that happened nationally it would be the end of Brexit.”
In what is likely to be seen as a swipe at Boris Johnson, Mr Hunt said: “We need to get real. We are facing a constitutional crisis.
“Our new Prime Minister will preside over a hung Parliament.
“A serious moment calls for a serious leader.”
Mr Hunt said he thought Brussels was ready to move on the Northern Irish backstop issue.
“They understand that the backstop is not going to get through Parliament,” he said.
“Choose me for unity over division, for experience over rhetoric, for tough negotiation over empty threats.”
He went on: “Our failure to deliver Brexit has put our country and our party in grave peril.
“The leadership I offer is based on one simple truth: without Brexit there will be no Conservative Government and maybe no Conservative Party.
“Whoever delivers Brexit will win the next election for the Conservative Party, but, without Brexit, no Conservative prime minister can win.”
Ms Mordaunt said of Mr Hunt: “I trust him on Brexit because I have seen him in Cabinet over the last year.
“It’s true he has credibility from all sides, but he also took a side. He fought for a deal but also knew that we had to leave no-deal on the table to secure a good deal.”