The prime minister put a slimmed down version of her deal to MPs, in a last-ditch attempt to meet an EU deadline to secure a short extension to May 22.
But her efforts ended in failure on the day the UK was originally scheduled to quit the EU, despite the reluctant support of hardline Brexiteers such as Dominic Raab, Boris Johnson, Jacob Rees-Mogg and Iain Duncan Smith.
A grim Ms May told MPs that they were “reaching the limits of the process”.
Asked whether an election was now becoming a clear possibility one Cabinet source told The Independent without hesitation: “Yes. Absolutely. No question.”
There has been speculation that the vote itself was set up for 29 March to make a show of Jeremy Corbyn’s party voting against Brexit ahead of a pending election campaign.
One cabinet minister later said: “We would throw at them the question of ‘what did your MP do on exit day?’
“This is going to be difficult for a lot of individual Labour MPs in Leave areas.”
Thousands of pro-Brexit protesters gathered in Parliament Square during the day, with many angry and confused over the gridlock in the House of Commons.
Jeremy Corbyn and SNP MPs also called for a general election to end the crisis.
Meanwhile, the European Council will meet to discuss the crisis on 10 April, Donald Tusk, the council president, said after the vote.
Theresa May now has until April 12 to offer new proposals to Brussels with new proposals.
A failure to produce any could see the UK leave without a deal that day.
If you would like to see how the day unfolded, please see what was our live coverage below: