Jon Snow, the anchor of Channel 4 News, posted a tweet on Tuesday morning saying a "lawyer contact" told him "the Attorney General said NO last night to the validity of Mrs May's "new European Union deal".he been told to go away and find a way to say YES".
The GBP/JPY cross plunged back below the key 145.00 psychological mark in the last hour, albeit quickly recovered few pips thereafter.
Most observers see it as highly unlikely the deal will pass through parliament and Mrs May's spokesperson has been forced to deny rumours the prime minister may delay the vote with only a couple of weeks to go until the United Kingdom leaves the EU.
The cross crashed around 320-pips, eroding a major part of the previous session's goodish up-move and was further pressurized by a modest pull-back in equity markets, which provided a minor lift to the Japanese Yen's safe-haven status. SNP MPs have reiterated calls for a second referendum, saying that the time has come for May to accept that a new referendum is necessary.
Leader o the opposition Jeremy Corbyn said: "This evening's agreement with the European Commission does not contain anything approaching the changes Theresa May promised Parliament, and whipped her MPs to vote for". Mrs May has struggled to get a legally binding guarantee from the European Union that the backstop would be temporary, as desired by Eurosceptic members of her party.
They have been demanding that the agreement does not keep the United Kingdom locked in the Irish backstop - an insurance policy to guarantee no return to a hard border in Ireland - indefinitely.
Attorney General Geoffrey Cox said last-minute new agreements "reduce the risk" of Britain being "indefinitely and involuntarily" held in the so-called Irish border backstop.
HuffPost UK understands the DUP can not back May's deal in light of Cox's advice, and are likely to be followed by scores of Tory Brexiteers who have said they will be guided by the Northern Irish party.
Groups of MPs are preparing to test their versions of Brexit via a series of amendments if it is clear May's deal is doomed.
"There should be no lingering doubts: this deal will leave us trapped and surrenders our sovereignty. Tomorrow, the House of Commons will debate the improved deal that these legal changes have created".
While the majority of analysts seem confident that May's deal will once again be shot down, Alastair George, chief investment strategist at Edison, argued on Tuesday morning that the EU's overnight concessions might be enough to win over a significant amount of MPs.
The changes fall short of demands of hardcore UK Brexiteers, but may persuade some politicians to switch their votes. Even with updated language on the Northern Ireland border, the vote could still fail, as most of the 585-page withdrawal agreement from January remains intact.