Conservative MPs have been warned not to rebel against the government as opposition MPs plan to introduce a law to stop a no-deal Brexit when parliament returns on Tuesday.
British MPs opposed to a no-deal Brexit will attempt to pass a law this week to stop Prime Minister Boris Johnson from letting Britain crash out of the EU on October 31, the opposition said.
But senior minister Michael Gove refused to guarantee the government would abide by any such legislation.
Johnson has pledged to deliver Brexit with or without a deal, but opposition MPs - and several from his own Conservatives - want to push through legislation to rule out no-deal before parliament is suspended in just over a week's time.
Labour Brexit spokesman Keir Starmer said the plan, which will be published on Tuesday, had one "very simple" aim - to stop Johnson taking Britain out of the EU without a deal.
"Obviously, if we are at the 31st of October, that will require an extension," Starmer told the BBC's Andrew Marr on Sunday.
"But I think this should be a very short, simple exercise designed to ensure we don't crash out without a deal."
Gove, one of Johnson's key ministers who is co-ordinating no-deal contingency plans, said he believed a majority of MPs would back the prime minister and defeat the attempt.
"We know the prime minister is making progress with our European friends and allies in attempting to secure a deal, and I don't believe that people will want to erect a roadblock in his way," he said.
Asked whether the government would abide by any legislation passed to prevent a no-deal Brexit on October 31, Gove said: "let's see what the legislation is that (Starmer) puts forward."
Starmer responded by saying it was "breathtaking" for ministers not to confirm the government would comply with legislation passed lawfully.
"No government is above the law," he said on Twitter.
Johnson told the Sunday Times that those backing the opposition to no-deal risked there being no Brexit at all.
"Are you going to side with those who want to scrub the democratic verdict of the people - and plunge this country into chaos?" he said.
"Or are you going to side with those of us who want to get on, deliver on the mandate of the people and focus with absolute, laser-like precision on the domestic agenda? That's the choice."
EU 'not optimistic'
The European Union will not change the divorce deal agreed with Britain, EU negotiator Michel Barnier said.
He insisted the agreement's most contentious element, a so-called backstop mechanism to keep the Northern Irish border open in all post-Brexit circumstances, was "the maximum amount of flexibility that the EU can offer".
Writing in the Sunday Telegraph, Barnier added that the provision must remain part of any deal but given British Prime Minister Boris Johnson's hostility to it he was "not optimistic" of avoiding Britain crashing out of the European Union on October 31.
Johnson, who took power in July calling for the backstop to be totally scrapped, has insisted the country will depart the bloc under any circumstances on the latest delayed deadline in order to honour the 2016 referendum when 52 percent of Britons voted to leave.
Jeremy Corbyn, leader of the main opposition Labour Party, has said he could also table a no-confidence vote in Johnson's government - which has a majority of just one - if required to stop no deal.