Electing Boris Johnson leader on a no-deal Brexit ticket would risk a permanent split in the Conservative Party, a former minister has warned.
The former foreign secretary has established himself as firm favourite to succeed Theresa May as prime minister in a contest many in Westminster expect to be triggered within weeks.
A poll conducted shortly after he confirmed he would stand on Thursday put him on 39 per cent support among party members, well ahead of his nearest rival Dominic Raab on 13 per cent.
But he must first win his way through an MPs’ vote onto the shortlist of two presented to the membership in the country.
Foreign secretary Jeremy Hunt is currently thought to be leading in the race to sign up MP supporters, with Mr Johnson, Mr Raab and Michael Gove grouped together some way behind, and a wide range of other potential candidates yet to make real inroads.
But Phillip Lee, who quit Ms May’s government last year over her EU withdrawal policy, told The Independent that Mr Johnson would risk the Conservatives’ hold on power and the future of the party if he took it down a no-deal route.
It would be a “sweet irony” if the Brexit figurehead found himself forced to deliver a Final Say referendum because there was no majority in parliament for no deal, he said.
“I don’t think it is necessarily a personality who splits the party, I think the policy might,” said Mr Lee, who now chairs the Right to Vote group of Tory advocates of a referendum. “I don’t think a no-deal Brexit leaves the party intact. If that becomes the policy of the winning candidate, expect interesting times to follow.”
Mr Lee – who has faced threats of deselection in his Bracknell seat – said he had not personally decided whether he could remain in a party led by Mr Johnson, but he said it was an active topic of conversation among concerned MPs.
“Don’t think that these conversations are not taking place,” he said. “They have been taking place for at least a year.
“Anybody who thinks that people don’t feel passionately about stopping no-deal Brexit in the Conservative ranks and aren’t prepared to throw themselves under a bus doesn’t understand the situation.”
Mr Lee predicted “confidently” that at least 20 Tory MPs would opt for a second referendum if the only alternative was no deal; perhaps enough to secure a fresh public vote.
When MPs voted on a referendum proposal in March it was defeated by 268 to 295. But Mr Lee said the vote was taken when Ms May’s “soft Brexit” alternative was still seen as a viable option.
The dramatic emergence of the Brexit Party under Nigel Farage had emboldened Tory Remainers by clarifying the options, he said. But he added: “Until soft Brexit 100 per cent disappears as an option, it remains a complicating factor.”
Labour MP Lloyd Russell-Moyle said he has had similar conversations: “There are many Conservatives who tell me that, when the crunch comes and if there is a more Brexity version put on the table by a new Brexity prime minister, they will come over to us on the confirmatory vote.
“We only need about 45-30, maybe, Conservatives to come over to us and we can achieve a majority in parliament.”
Although a no-deal Brexit is hugely popular among rank-and-file Conservatives, some of the party’s MPs are wary of a policy that might win them enhanced majorities in core Leave-voting areas like Lincolnshire but cost them seats in London, the southwest and Scotland.
Despite Mr Johnson’s declaration on Thursday and the collapse of cross-party Brexit talks on Friday, the race for the succession remains a phoney war.
Friends of the Uxbridge MP said he had not intended to use his appearance at a conference in Manchester as a stage to announce his intentions, but had simply decided to answer the question straightforwardly if he was asked if he would stand.
Few in Westminster will have missed the signs of rival camps being established in anticipation of a battle for the crown following Ms May’s fall. But despite the conversations in tea rooms and the “beauty parade” speeches by would-be contenders, the race is yet to begin in earnest.
“With it being a cold war for so long, everyone is up and ready, but no one is going to precipitate anything,” said one source.