The prime minister, which has been under a storm of criticism ever since she presented the original agreement, promised to secure legally binding and significant changes to the backstop. European commission president Jean-Claude Juncker has said that the Commons would have "no third chance" on May's deal.
The North West Cambridgeshire MP said: "Given no-deal Brexit is the Government's default position, will the Prime Minister kindly inform the House she will instruct the Chancellor to make available whatever funds are required to ensure the country is as best prepared as possible in the event we do leave on a no-deal basis".
The PM said she "profoundly regrets" that her deal was voted down but added Tory MPs will get a free vote on a no-deal Brexit today, meaning they can vote with their conscience rather than follow the orders of party managers.
'We can not continue to behave like this as a government, ' he said.
"The government has been defeated again by an enormous majority and it must accept its deal is clearly dead and does not have the support of this House", said Labour leader Jeremy Corbyn, whose party voted against the deal.
But although she managed to convince about 40 Tory MPs to change their mind, it was not almost enough to overturn the historic 230 vote defeat she suffered on the same deal in January.
Speaking after the vote, Eastern region Labour MEP Alex Mayer said: "Not a single sentence, word or comma changed in the withdrawal agreement text since the last time Theresa May put the deal to Parliament".
Pleas ignored Mrs May begs for support and vote result announced
What isn't clear is how the prime minister actually intends to dig herself out of this terrible political hole.
A No 10 spokesman said she did not discuss resigning after her latest defeat because her government had recently won a confidence vote in the Commons.
MPs have dramatically rejected crashing out of the European Union without a deal at any time and under any circumstances.
Corbyn added: "She needs now to show leadership".
Ed Miliband, Doncaster East MP; Sarah Champion, Rotherham MP; John Healey, MP for Wentworth and Dearne, and Barnsley MP Dan Jarvis voted against the deal.
If that happens, MPs will vote on Thursday on extending article 50 which triggered the UK's exit process from the EU. The lawmakers then supported the idea of replacing the backstop provision, which has caused the most controversy in parliament, with alternative arrangements.
Instead "we hear it in briefings in Brussels in bars", she said, in reference to an overheard conversation involving her chief Brexit negotiator Olly Robbins about no deal.