Mrs May told MPs they would vote tomorrow night on a motion that states: "This House declines to approve leaving the European Union without a Withdrawal Agreement and a Framework on the Future Relationship on 29 March 2019; and notes that leaving without a deal remains the default in United Kingdom and EU law unless this House and the EU ratify an agreement". "She is simply saying it reduces the chances of us being kept in the backstop", Wilson told LBC radio, in reference to the so-called "Irish backstop" - the policy within the Withdrawal Agreement aimed at making sure no hard border appears between Northern Ireland and Ireland.
Lawmakers voted by 391 to 242 against the deal, the second time they have defeated it.
The advice was issued the morning after Mrs May's dash to Strasbourg to finalise a deal with Jean-Claude Juncker which she said would deliver "legally-binding" reassurances for MPs to ensure the Irish backstop can not be permanent.
British lawmakers, who on January 15 voted 432-202 against May's deal, are studying the assurances and Cox's legal advice before the vote later on Tuesday. The so-called "backstop" solution for the Irish border - created to avert sectarian violence from returning to Northern Ireland - is opposed by more ardent Brexit supporters. "There will be no further interpretations of the interpretations; no further assurances of the re-assurances - if the meaningful vote tomorrow fails".
"There will be no third chance", he said.
The United Kingdom's tortuous crisis over European Union membership is approaching its finale with an extraordinary array of outcomes still possible, including a delay, a last-minute deal, a no-deal Brexit, a snap election or even another referendum.
In 2016, 52 percent of Britons voted to leave the E.U. Forty-eight percent voted to remain in the group. But it has proven to be a major stumbling block in the British government's quest for a divorce deal.
And he said that "the legal risk remains unchanged" that if no such agreement can be reached due to "intractable differences", the United Kingdom would have "no internationally lawful means" of leaving the backstop without European Union agreement.
The immediate reaction was cautious from Brexit-supporting lawmakers in her own party and from the Northern Irish Democratic Unionist Party which props up her minority government.
Germany and other EU nations welcomed the overnight agreement reached between European Commission President Jean-Claude Juncker and British Prime Minister Theresa May as a last-ditch effort to avoid a chaotic Brexit at the end of the month.
The joint UK-EU statement in the non-binding political declaration commits both sides to develop new technologies at the border to replace the need for the backstop by December 2020.
"I have got to say that if you look at what the prime minister has said so far it seems to fall short of what she, herself, had promised".
The British government's top lawyer, Attorney General Geoffrey Cox, is due to set out his legal analysis of the assurances ahead of Tuesday's vote.
EU Parliament President Antonio Tajani said the problems raised by the attorney general are "an internal problem of the U.K." and would not prompt the EU to reconsider the Brexit deal again. Many pro-Brexit lawmakers will wait to see that before deciding how to vote.
Brexit will pitch the world's fifth largest economy into the unknown and many fear it will serve to divide the West as it grapples with both the unconventional presidency of Donald Trump and growing assertiveness from Russian Federation and China.