MPs will hold a showdown Brexit debate tomorrow amid frantic last-minute talks to try and pass Theresa May's deal.
But confusion and anger erupted today after it emerged that would not actually be a "meaningful vote" on the 585-page pact with the EU.
MPs had been tipped to hold a third "meaningful vote" on the deal - twice defeated - tomorrow afternoon after Theresa May dramatically vowed to resign if it passed.
It would have set up a historic showdown where, if she won, the Prime Minister would quit within a few weeks.
Yet she faced defeat after despite her pledge winning some Tories, the DUP and around 30 Brexiteers Brexit: Theresa May's last gamble in tatters as resignation plan is not enough
So today, in a shock development, Commons Leader Andrea Leadsom repeatedly REFUSED to say the crucial "meaningful vote" will take place tomorrow.
Brexit: What the hell happened last night and what happens now?
Brexit: 5 fast facts you need this morning as Theresa May plays her final card
Instead the Leader of the Commons announced - in vague terms - that there will be a debate on a motion on Brexit .
She admitted the motion has not been "finalised" and discussion are "ongoing", despite a 5pm deadline today for Theresa May to table it in full.
And a Downing Street source later said it would NOT be a full-blown meaningful vote on the Brexit deal.
This deliberate lack of clarity has prompted furious speculation that the government is trying to "uncouple" the two parts of its Brexit deal.
Mrs May's key ally hinted she could try and force MPs to vote on the 585-page "withdrawal agreement", but not the "political declaration" that comes with it.
David Lidington said today: "If you believe in delivering the referendum result by leaving the EU with a deal, it is necessary to back the withdrawal agreement.
"For whether a particular MP wants the final destination to look like Norway, or look like Canada or look like the proposals in the Chequers white paper, the starting point is the Withdrawal Agreement itself."
Brexit: Theresa May's last gamble in tatters as resignation plan is not enough
Brexit indicative vote results confirmed as MPs vote against EVERYTHING
This "uncoupling" could be a bid to win over Labour MPs, who largely back the withdrawal agreement but not the political declaration.
But today furious Labour MPs said such an "uncoupling" would be illegal - because UK law says both elements must be voted on together.
Labour MP Ben Bradshaw warned of "more attempted trickery and potential illegal trickery by the government", saying an uncoupling would be "completely intolerable, not only potentially illegal".
And he said it would be "asking this house to vote for a completely blind Brexit".
Labour MP Chris Bryant accused the government of "shenaniganating".
A Labour spokesman said: "We strongly oppose any attempt by the government to decouple the withdrawal agreement from the political declaration, which would hand the Tory party a blank cheque for a blindfold Brexit."
The desperate 11th-hour wrangling comes ahead of the EU's deadline to pass the Brexit deal by 11pm tomorrow, in order to secure a Brexit delay to May 22.
Ms Leadsom also confirmed MPs' Easter break is cancelled - for now.
The Commons was meant to head off on a two-week holiday in the first week of April.
But the EU has set a new Brexit deadline of April 12 if no deal is agreed this week. At that point the government must choose to Revoke Article 50, crash out with no Brexit deal, or agree a second "long extension" with the EU.
Ms Leadsom admitted the Commons "rightly needs time to address our exit" and "our constituents will expect parliament to work flat out to do so".
Despite the confusion, Mrs May's announcement that she could has prompted furious speculation about potential Tory leadership candidates.
Tory Brexiteer Dominic Raab declared "this is a time for pragmatism and realism" and called for the UK to "go back to the EU again" seeking "a legally binding exit from the backstop".
That is despite the EU refusing to say it will do any such thing.
And Boris Johnson, despite swinging behind the deal last night, has privately told friends it is "dead", the Evening Standard reported.
Meanwhile, oft-tipped Michael Gove was pictured literally running, out for a jog.
But Jacob Rees-Mogg ruled out standing for the leadership, telling TalkRadio: "My hat will remain firmly on my head."
Next Conservative leader odds: Runners and riders to replace Theresa May
How does a Tory leadership election work? Rules for dramatic contest explained
The failure to clarify tomorrow's vote prompted a row today at Business Questions in the House of Commons.
Labour Shadow Commons Leader Valerie Vaz said: "We need more clarity on what exactly this motion is about."
She demanded to know if it would be "the full package" or more vague.
Yet Commons Leader Andrea Leadsom refused to clarify.
Instead she only said a motion would "comply" with the ruling by Speaker John Bercow, that the third meaningful vote must be "substantially" different to the previous two.
The House of Commons leader said: "We recognise that any motion brought forward will need to be compliant with the Speaker’s ruling and that discussion is ongoing."
Brexit settled status explained: EU citizen registration rules and when you should apply
What is a No Deal Brexit? 21 ways you'll be affected if UK leaves EU with no deal
A spokeswoman for the leader's office failed to clarify in a later statement.
She said: "Tomorrow's motion will need to be compliant with both the Speaker's ruling and the EU Council's decision on conditionality relating to exit on 22 May.
"Discussions are ongoing and we will look to table the motion as soon as possible today, in order to avoid asking for another extension and the requirement to undertake European Parliament elections."
