The message to the Prime Minister was issued by former attorney general Dominic Grieve, a ringleader of rebel Conservatives in the Commons.
Labour’s conference decision to keep open the option of a second referendum - including the potential to abandon Brexit altogether and remain in the European Union - indicates there could be a parliamentary majority in favour of another vote, Mr Grieve said.
Writing in the Sunday Telegraph, Mr Grieve said opposition to the Prime Minister’s Chequers plan in both EU capitals and Westminster meant a so-called People’s Vote could be the only alternative to a no-deal Brexit.
He said: “I believe the time has come for a polite rebellion by pragmatic Conservatives.”
It was clear that “there is a significant group of Conservative MPs who think that a People’s Vote- a vote on the final form Brexit will take - is absolutely indispensable for the future wellbeing of our country”.
He added: “A no-deal Brexit is a proposal so damaging to our future that it cannot be accepted.
“So the only possible response must be to return to the British electorate and ask them what they want. That, it seems to me, is good pragmatic Conservative position.”
Mr Grieve warned that the crisis over Brexit was “paralysing government” and damaging the Tories’ reputation.
“ It reduces our reputation for quiet effectiveness in delivering positive change for our country,” he said.