John Downing: 'If Westminster parliament votes against May's Brexit deal, what happens next would depend on just how badly the pound tanks'
It took just 38 minutes to put the UK beyond the Brexit point of no return yesterday after almost 46 years of EU membership. All the Euro kingpins honoured their commitment to strike a sombre tone at this special Sunday summit in Brussels, with much talk of there being "no winners".
EU Commission President Jean-Claude Juncker and chief Brexit negotiator Michel Barnier gave their best 'whistling past the graveyard' efforts.
Both made the unlikely claim that the draft Brexit deal will pass the next test by being ratified in the British parliament early next month.
Pigs are more likely to fly than Theresa May's chances of getting this deal through Westminster. Her parliamentary arithmetic is truly abysmal.
The contrast between London and the other EU member states is now vast and complete.
The EU 27 have shown extraordinary unity and discipline over Brexit during the past 20 months of tough negotiations. The UK has been divided and confused.
That same EU unity of purpose was again evident yesterday with the speed of this decision and a resolute vow from all the leading players that it was "this deal or no deal".
We can totally discount the last-minute Spanish strop over Gibraltar as just an incident for the optics of internal politics.
The experience of these past 20 months of negotiations is surely a warning to other member states which might be tempted to follow the UK out of the European Union.
The reality is that the UK is getting the worst of all worlds as they must obey EU rules they used to be able to amend, shape, and even veto.
They are not getting their cake and eating it, as former foreign secretary Boris Johnson boasted on the Brexit campaign trail.
Back in Westminster, Mrs May's numbers tale of woe goes like this. There are officially 650 parliament seats. Allowing for boycotters, like the seven Sinn Féin MPs, other absentees and vote abstentions, it is generally agreed some 320 votes are needed to win.
There will be defections from Mrs May's 315 Conservatives and the 10 Democratic Unionist Party MPs, propping up her minority government, are sworn to vote against it.
She is unlikely to benefit from too many defectors from Labour's 257 MPs or the 12 Liberal Democrats. It is both those parties' policy to vote No to this deal.
The Scottish National Party has 35 MPs but is miffed over Northern Ireland getting better treatment than Scotland, and EU countries getting fishing waters access.
Tensions over fisheries could also threaten the support of the 13 Scottish Conservative MPs.
It's a hell of a hill to climb and it's very hard to view the vote in London, to be held around December 10, as anything other than a lost cause.
What would happen then? Well, right now it is anybody's guess.
The eloquent President of Lithuania, Dalia Grybauskaité, stopped on her way into this meeting and summarised the possibilities for the journalists at the EU conference centre. Ms Grybauskaité is a former EU commissioner and knows a thing or two about how the system works.
She said the European Union should anticipate at least four scenarios after this leaders' summit which signed off on the Withdrawal Agreement, clearing the way for the UK's exit and assuming Theresa May fails in Westminster.
These scenarios include a new general election in the UK or even a second Brexit referendum. "Everything could happen, at least four possible scenarios could be in place, but it's up to the British side to decide what path to choose," the Lithuanian president said.
"It could be a second vote of the people, it could be new elections, it could be a request for renegotiations. There are at least four scenarios, I calculate," she said.
For all her erudition, Ms Grybauskaité was wide of the mark in anticipating renewed negotiations on the 585-page deal agreed yesterday.
There was unanimity that it cannot and will not be re-opened - and a no-deal Brexit is more likely than that.
That was one scenario she did not explicitly voice and it is the outcome most Irish people dread.
Commenting on that grim prospect in the Dáil last week, the Taoiseach said he thought there would have to be 'no deal' talks between the EU and the UK in such an eventuality.
In sum, he was saying last week, an utterly 'no deal' outcome was simply unthinkable. Some kind of makeshift arrangement would have to be made.
But that is also a heck of an assumption to make and by yesterday he was not keen to revisit this speculation, preferring to stress the prospect of Mrs May somehow doing a Westminster miracle.
The final act of the EU end of Brexit will come next February when the European Parliament is likely to ratify this draft deal. That is assumed to be a fait accompli and the real battles are all now in London.
A popular scenario in London political circles over the past week was that Mrs May's deal might pass parliament the second time around, after initial failure. The thinking there is that the markets might react violently to a parliamentary No vote and the pound might tank.
That would put the frighteners on MPs enough to have them revisit the deal and pass it second time around.
The obverse of that theory is that the markets might be anticipating a second vote, so the pound may not fall through the floor first time round. Those MPs just might not be frightened enough.
One thing we can predict is that this will continue to be very noisy indeed. The weekend also saw the rhetoricometer doing handstands with ultra-Brexiteer Boris Johnson in Belfast to address his "fellow unionists" at the DUP conference.
The DUP did pump up the anti-deal rhetoric and party leader Arlene Foster said it may pull the rug from under Mrs May's minority government, which they have been propping up since June 2017.
Earlier, Ms Foster had gone so far as to say that a Labour government under Jeremy Corbyn was a bad scenario - but preferable to passage of this Brexit deal.
That does not look like promising ground for Mrs May. But another thing we can predict is that she will continue to fight her case.
She has clearly gained in popularity with the electorate for her courage and she has absolutely nothing to lose.
We can expect that she will begin the old game of bribing, cajoling and bullying waverers to back this deal. She will galvanise her party middle ground with an insistence it is this deal - or no deal. It will be garnished by dire warnings that Labour are waiting in the wings.
Will that be enough? Well maybe, or maybe not. It will be very interesting to observe from this side of the water.