On December the 11th MPs will each cast their meaningful vote on Theresa May’s Brexit deal.
If - against all the odds - she gets it through, then it’s game on.
The Withdrawal Agreement should be written into law before Brexit Day on March the 29th when a 21-month transition period will then begin.
But what happens if, as expected MPs reject her deal?
Teresa May could go away, speak to the EU, make some tweaks and bring her deal back for a second go.
But her authority will be severely damaged and she’s likely to face a leadership challenge from her own MPs.
Labour could force a vote of no confidence in her government in the hope of triggering a general election.
Momentum for a second referendum is likely to gather pace and increase in support.
Otherwise Britain could crash out without a deal on March the 29th.
Though there are probably too many MPs against that idea to allow it to happen.
But, as the last two years have taught us, when it comes to Brexit anything is possible.