The House of Commons was supposed to vote on the deal Tuesday evening and it was widely expected to go down to a resounding defeat as almost half of Ms. But the reason it insisted on the backstop that Brexiters so dislike - to keep the Northern Ireland border frictionless - will not go away and must still be solved.
A spokesman for Tusk said the timing of the meeting, which will come on the first day of a planned European Council summit, was still to be determined.
"Just finished a call with the Prime Minister", Arlene Foster said on Twitter.
"If you truly want "the will of the British people" to be implemented, you'll be happy to have a second referendum to confirm what their will is", Rowling tweeted.
EU leaders have rejected the prospect of renegotiating the withdrawal agreement itself but European sources speaking privately say tweaks in the accompanying declaration on post-Brexit ties might be possible. News of the delay sent the pound tumbling to a seven-month low against the dollar.
Sterling skidded to its weakest level since June 2017, falling to $1.2622.
Carolyn Fairbairn, head of the Confederation of British Industry, said the delay was "yet another blow for companies desperate for clarity". "She's saying to MPs, "look it's this or nothing", Wager told Al Jazeera.
"So the government will step up its work in preparation for that potential outcome".
May's own position is uncertain and she could face a swift challenge.
Earlier today, Donald Tusk said that the European Union will not be renegotiating the Withdrawal Bill proposed by May.
She said that while many aspects of her plan enjoyed "broad support" among her colleagues, she acknowledged that the question over the Irish border continued to provoke "widespread and deep concern".
"I think most people want us to do this, to get it done and get it all wrapped up by Christmas and actually focus on the future", she said.
If she's not back before December 20, the government's leader of the house later clarified, MPs will go on holiday and won't reconvene until January 7.
He questioned what she could achieve by going back to the European Union leaders.
Another potential obstacle, however, is that Britain would have to continue paying large amounts of money into the European Union budget which would prove hugely unpopular.
"Our country deserves better than this".
May's office insisted Monday morning that the vote would definitely be held, but the BBC and other outlets reported it would be postponed.
The leader of the opposition Labour Party, Jeremy Corbyn, said Britain no longer had "a functioning government" and called on May to "make way" for a Labour government.
Boris Johnson, the former foreign secretary, said Britain will be open to "blackmail" if the deal is approved.
Rudd, who backs May's Brexit deal, said "anything could happen" if the government is defeated in Parliament, and predicted a chaotic period.
"We can not continue like this".