Senior Tory MP Sir Oliver Letwin has said he does not support Jeremy Corbyn becoming a caretaker prime minister in a bid to avoid a no-deal Brexit.
But he supported discussions across the Commons to prevent the UK crashing out of the EU without a deal.
Prime Minister Boris Johnson has pledged that the UK will leave the EU by 31 October “do or die”.
Mr Corbyn’s current plan is to win a no-confidence vote in the government and become interim prime minister.
He then wants to delay Brexit, call a snap election and campaign for another referendum.
Sir Oliver, who was among senior Tories who received a letter from Mr Corbyn about the plan, told BBC Radio 4’s Today programme: “That appears to be his agenda. I have to say it is not one I personally share.
“I don’t think it’s at all likely that a majority would be formed for that and I personally wouldn’t want to vote for it. I wouldn’t be able to support that, no.”
Sir Oliver, a former minister, has led several attempts in Parliament to break the Brexit impasse and prevent a no-deal Brexit.
But he said he was “not very inclined” to bring down the government in a no-confidence vote and would “rule it out” if it led to Jeremy Corbyn being in Downing Street.
His comments come amid a row among MPs who oppose no deal, with Liberal Democrat leader Jo Swinson initially dismissing Mr Corbyn’s plan as a “nonsense”.
She suggested Tory grandee Ken Clarke or former Labour deputy leader Harriet Harman could head a temporary government instead.
On Friday, Mr Clarke said he was willing to lead a government of national unity to avoid a no-deal Brexit.
Sir Oliver suggested the majority of MPs did not want a no-deal Brexit and they needed to “talk a lot” and “talk frankly” to come to an agreement.
However, fellow Tory MP – and Brexiteer – Sir John Redwood told Today he was not worried about opposition to the government’s Brexit stance.
“I note that all Labour and all Conservative MPs in [the 2017 general election] were elected on manifestos that said they would support our leaving the European Union because that was the wish of the British people expressed in a decisive referendum”.