MPs have voted to rule out a no-deal Brexit under any circumstance in another major defeat for Theresa May.
After the so-called Spelmen amendment was passed by only 4 votes, Conservative MPs were whipped to vote against the government's own motion.
However several government ministers, including at least three cabinet ministers, are reported to have abstained or even broken the Conservative whip to definitively reject a no-deal Brexit.
The motion passed by a majority of 43, with 321 votes for and 278 votes against.
Mrs May told MPs: "The legal default in UK and EU law is that the UK will leave the EU without a deal unless something else is agreed.
"The onus is now on every one of us in this house to find out what that is."
MPs will vote tomorrow on extending Article 50.
MPs have voted to reject a no-deal Brexit under any circumstance by a narrow majority.
The so-called Spelman amendment was passed by only 4 votes, with 312 voting in its favour to 308 voting against.
Although not legally binding, this vote will create huge political pressue on Theresa May to rule out no-deal Brexit.
Yvette Cooper has moved the so-called Spelman amendment after the original proposer, Consevative MP Dame Caroline Spelman, said she was no longer putting it forward.
The Spelman amendment rules out the prospect of a no-deal Brexit under any circumstance, going further than the government's motion.
Conservative ministers had reportedly pressured Dame Caroline to withdraw the amendment for fear it would split the party.
However Dame Caroline was informed by the Speaker that the amendment was now "in the hands of the house".
Dame Caroline Spelman attempted to withdraw her amendment.
Former Conservative minister Dame Caroline Spelman told MPs she will be withdrawing her amendment from today's vote.
The so-called Spelman amendment goes further than the government's own wording in ruling out a no-deal Brexit in any scenario.
Ministers had told Conservative MPs to vote against the amendment, and there was speculation that Dame Caroline was being pressured to drop it.
Dame Caroline told MPs she believed Mrs May's statement offered a greaer opportunity to obtain a "really large majority" against no-deal.
However John Bercow said the amendment could still be moved by other MPs if they chose to.
Michael Gove told MPs that as a result of the government's defeat last night, there were "no easy options or attractive choices left".
Standing in for Theresa May during the debate on no deal, the DEFRA secretary said: "We all need to recognise that leaving on March 29 without a deal would impose economical, political and constitutional risks for this country that I don't believe we should undertake.
"I therefore think it is important that all of us work across this house and across old divisions to try to seek a consensus."
The debate continues in the House of Commons, with MPs expected to vote on whether to accept a no-deal Brexit at around 7pm.
The House of Commons Brexit committee has issued an emergency statement following the government's defeat last night.
The committee, chaired by Remainer Dominic Grieve, calls on the House to support an extension to the Article 50 process.
The committee recommends the government hold a series of indicative votes to give clarity on what the extension will be used for.
If MPs vote to extend Article 50, the commitee recommends seeking an extension beyond the end of May, and therefore "the UK should be prepared for the possibility of having to hold these elections at the end of May."
During Prime Minister's Questions, Theresa May made reference to her increasingly croaky voice to make a point about Brexit.
"I may not have my own voice but I do understand the voice of the country," she told opposition leader Jeremy Corbyn.
The joke attracted jeers from across the House of Commons.
Mrs May has been losing her voice over the past couple of days, seemingly due to the same ailment that plagued her during the 2017 Conservative Party conference.
The full letter posted on Mr Tusk's Instagram account
Donald Tusk has trolled the Prime Minister with a letter he received from a six-year-old in London.
Posting on his Instagram account, the European Council president shared a picture of the handwritten letter he had received from London resident Sophie, which asks whether the UK and EU can still "be friends" after Brexit.
Tusk captioned the image "We will always be friends, Sophie", along with a heart emoji.
It isn't the first time Tusk has used his Instagram account to goad Mrs May, having previously posted a picture of himself with the Prime Minister sharing cake with the caption: “A piece of cake, perhaps? Sorry, no cherries".
Former Conservative PM David Cameron
David Cameron has warned that a no-deal Brexit would be a "disaster" for Britain.
The former Conservative Prime Minister said he backed Theresa May's attempts to secure a deal, despite her Withdrawal Agreement being rejected by MPs for the second time last night.
"Obviously what needs to happen next is to rule out no deal, that would be a disaster for our country, and to seek an extension and I'm sure that's what's going to happen next," he told Sky News.
What happened last night?
Theresa May leaves Number 10
MPs gathered at the House of Commons last night for a meaningful vote on Theresa May's Brexit deal.
The deal was defeated by a majority of 149 votes, with with 391 voting against the withdrawal agreement, and 242 voting in favour.
Among those who voted against the deal were 75 Conservative MPs and the entirety of the Independent Group.
As a result of the last night's vote, MPs will now have to decide whether they want to rule out a no-deal Brexit, or if they are happy to leave the European Union without a deal.