After buying time two weeks ago, when she won a vote giving her the mandate to reopen talks with the bloc, the embattled premier is expected to ask Parliament to restate its demand to remove the backstop from the Withdrawal Agreement and to promise a further vote if she hasn't brought a renegotiated deal back to Parliament by Feb 27.
That's a big number that is likely to concentrate minds on all sides of the Brexit discussions as Britain's March 29 date of departure nears.
Meanwhile, Mrs May has offered further talks with Labour in an attempt to secure cross-party consensus on Brexit.
And Labour leader Jeremy Corbyn suggested the PM was "running down the clock" on Brexit in the hope that MPs will be "blackmailed" by the fear of a no-deal outcome into supporting "a deeply flawed deal". The U.K. government canceled a £13.8 million ($18 million) contract with Seaborne Freight, a startup company that doesn't own any ships, to deliver backup ferry service in the event of a no-deal Brexit.
From there, he runs the day-to-day Brexit negotiations.
MPs are due to vote on Thursday on a government motion, reaffirming their conditional acceptance of May's deal, if she secures changes to the controversial backstop.
May told Parliament on Tuesday if she had not yet reached a deal in Brussels, she would deliver another progress report on February 26 and provide another chance for parliament to express its opinion on her approach the following day.
However, the European Union has repeatedly said the withdrawal agreement, sealed by the EU-27 leaders after 18 months of negotiations between the United Kingdom and the European Union, is not going to be reopened.
"This time that remains is extremely short", he added.
But Mrs May responded: "In most circumstances, that period may be important in order for this House to have an opportunity to study that agreement".
"While we will follow normal procedure if we can, where there is insufficient time remaining. we will make provision in the Withdrawal Agreement Bill, with parliament's consent, to ensure that we are able to ratify on time to guarantee our exit in an orderly way", May said.
Media captionConfused by Brexit jargon?
It said it had reached a range of agreements with London aimed at ensuring "that the existing mutual rights and obligations in its relationship with the United Kingdom will continue to apply as far as possible after the United Kingdom leaves the European Union, and to expand them in certain areas".
Economists say a no-deal Brexit would affect more than 100,000 jobs in Germany that depend on trade with Britain, with the auto industry hardest hit.
A cross-party group of MPs is to launch a fresh attempt to prevent a no-deal Brexit if Theresa May can not reach an agreement with Brussels by mid-March. "The meaningful vote will come back just as soon as it possibly can", the leader of the House of Commons, Andrea Leadsom, told BBC radio. Pro-EU Tories who aren't that keen on rebelling might be convinced to give May some breathing space and see what concessions she drags out of Brussels by then.
"The Prime Minister is pretending there is progress in the talks".
Mrs May rejected automatically following European Union rules on workers' rights and environmental protection but "in the interest of building support across the House" she said the Government is prepared to commit to asking Parliament if it wishes to follow suit if standards change.
"There's little doubt Brexit uncertainty is responsible for the disappointing numbers, though concerns over global trade will also have played a part", said Brettell.
Laughing as he spoke, he said: "It is, in fact, the same protagonists for Brexit and a no-deal who do not have the courage either to put the issue to a peoples' vote".
"We need to get on with the job of delivering Brexit for the British people and building a better future for this country", she said on the steps of Downing Street in the wake of the result, a huge Christmas tree in the background failing to add much festive cheer to the occasion.