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While a parliamentary technicality, it led to a vote in which another tranche of Tories rebelled, 17 this time, and which means that rather than having 21 days to come up with a Plan B if her deal is rejected next Tuesday - as is widely expected - the Prime Minister will have just three.
On Wednesday, Austrian Chancellor Sebastian Kurz said the United Kingdom may need to request a postponement of Brexit day if deadlock in Westminster continues and the risk of the United Kingdom leaving on March 29 without a deal becomes more likely.
May postponed a planned vote on the deal in December after conceding it was set to be defeated, and is now seeking assurances which she hopes will persuade lawmakers to back the agreement when they vote on it on January 15.
His call came as Nick Timothy - who was formerly one of Mrs May's closest advisers - said that he did not believe the British Prime Minister would "willingly" allow a no-deal Brexit.
An alliance of governing Conservative and Opposition legislators has dealt Mrs May two defeats in as many days - symbolic setbacks that suggest a power shift from the executive to the legislature.
She repeated that resolve during a noisy Prime Minister's Question Time in the House of Commons, telling the main opposition leader, Labour's Jeremy Corbyn, and other MPs that the best way to avert a no-deal Brexit was to vote for her deal.
On Wednesday, Parliament voted for an amendment calling on the government to set out its Plan B within three working parliamentary days of the January 15 vote, rather than the 21 days specified in Brexit law.
The business body has warned that Brexit would have profound economic consequences on the United Kingdom and has urged MPs to back Theresa May's deal.
Brexiteers accused speaker John Bercow of anti-Brexit bias when he apparently ignored the advice of parliamentary officials and selected the amendment demanding May bring forward new plans in the event of defeat.
The interventions seem unlikely to be enough to help May's unpopular agreement pass Parliament when it's put to a vote in the House of Commons on Tuesday.
"If, as is likely, an attempt to hold a General Election fails, it is incumbent on the Labour leadership to immediately throw its support behind a people's vote and campaign to remain in the European Union". "These discussions have shown that further clarification on the backstop is possible, and those talks will continue over the next few days".
The vote significantly increases the possibility of Theresa May calling for either a second referendum of a snap General Election to break the deadlock.
Elsewhere, Nick Timothy, Mrs May's former chief of staff, wrote in the Daily Telegraph that the Prime Minister would not willingly take the United Kingdom out of the European Union without a deal. Economists and businesses warn that would cause economic turmoil, as goods moving between Britain and the European Union suddenly faced customs checks, tariffs and other barriers.
The Shadow Brexit Secretary added: "Leaving with no-deal would be catastrophic".
But there is no clear majority for any single alternate course.
Japan's Prime Minister has said that his country offers its "total support" to Theresa May's EU Withdrawal Agreement.
Corbyn said if May had confidence in her deal, she should "call that election and let the people decide".
This is while Honda announced that it would put production on hold for six days in April due to Brexit and the delays it could cause on the Dover-Calais freight route.
He said: "It is a matter for the representative and champion of Parliament, it is not a matter for a representative of the executive branch - who is the executive's representative in the chamber of the House of Commons".