MPs have tonight dramatically rejected crashing out of the European Union without a deal at any time and under any circumstances.
In a surprise move, the Commons voted 312 to 308 - a majority of four - in favour of an amendment tabled by Tory former cabinet minister Dame Caroline Spelman.
And when the amended motion was voted on a few minutes later it passed by 321 votes to 278, despite the Government changing its position to whip against it.
Dame Caroline attempted to withdraw the amendment, but it was moved by fellow signatory, West Yorkshire MP Yvette Cooper and won the support of a majority of MPs during a string of crunch Brexit votes on Wednesday evening.
The amendment, which is not legally binding, was added to a Government motion tabled by Theresa May which would have rejected no-deal on the scheduled Brexit date of March 29 but left it on the table for other times.
It clears the way for the Prime Minister to bring forward a motion for debate tomorrow on whether Parliament wants her to seek a delay to Brexit by requesting an extension to the two-year Article 50 negotiation period.
However no-deal remains the default option unless an extension is agreed with the 27 other EU states, or a deal is passed before the end of the month.
To avoid a walkout by Cabinet ministers who oppose a no-deal Brexit, Mrs May initially gave Tories a free vote on the Government motion.
But this was transformed into a three-line whip to oppose the amended motion.
To avoid a walkout by Cabinet ministers who oppose a no-deal Brexit, Mrs May has given Tories a free vote on the Commons motion.
The wording of the motion declared the Commons "declines to approve" leaving without a deal on March 29 - but notes that remains the default position unless an agreement is reached.
Members of the Malthouse Compromise group of Tories from both Leave and Remain wings have tabled an amendment calling for Brexit to be delayed until May 22, followed by a "standstill" agreement lasting as late as the end of 2021, during which the UK would observe EU rules and pay into Brussels budgets while a full trade deal is negotiated.
The EU has already rejected the idea, which it views as amounting to a transition period without a formal Withdrawal Agreement.
Former Brexit minister Steve Baker, one of the amendment's backers, said "negotiability is a dynamic concept".