Why May's Brexit deal is set to be defeated in Parliament

First things first, there has been a widespread misunderstanding of why Angela Merkel made it known yesterday that if the Brexit deal - Withdrawal Agreement and Political Declaration - wasn't done and dusted by today, she would not be bothering to turn up in Brussels to formally ratify it on Sunday.

Her conspicuous intervention was not aimed at putting pressure on Theresa May to be more emollient in the last leg of negotiations.

The German Chancellor was in fact asking the likes of the Spanish premier Pedro Sanchez to stop misbehaving and causing unnecessary bother (Sanchez has been playing to a domestic audience by saying he would block any agreement that deprived him of a veto on the future of Gibraltar).

"The chancellor was doing the PM a favour" said an official.

Donald Tusk has passed the agreement on to the EU 27. Credit: AP

It worked. May will go to to Brussels on Saturday for talks that are more about style than substance with the president of the European Commission Jean-Claude Juncker, before signing it all off with the EU 27 on Sunday.

This means that after almost 20 gruelling and volatile months of talks, we now have 585 legally binding pages on the terms for the UK's exit from the EU and 26 non legally binding pages on the "framework for the future relationship" between the EU and UK.

The 26 pages are the new ones. And in many ways they are the most important, because they are the basis for judgements about whether the UK will be richer or poorer, safer or more vulnerable when outside the EU.

So what do we learn from them?

They confirm that May's Chequers plan, which proposed a "common rulebook" between the EU and UK to deliver wholly frictionless trade in goods between the UK and EU, is dead.

There is no promise in the Political Declaration (PD) to the UK enjoying "frictionless" trade, even as a possible outcome. And that is because May's proposal was seen as an attempt by the UK to enjoy the full benefits of the single market in goods without signing up for the obligations, most notably freedom of movement in people.

May will go to to Brussels on Saturday for talks with the president of the European Commission Jean-Claude Juncker. Credit: PA

So what the PD allows for is a future trade deal that could be similar to the free trade agreement enjoyed by Canada or deeper and richer than that - but not as deep and rich as full membership of the customs union and single market.

Quite how deep and rich it will turn out to be will depend on the extent to which government of the UK is prepared - in talks that will start after the UK leaves the EU on March 29 2019 - to follow rules set by the EU on competition, environmental and consumer standards, employee protection and so on.

Or to put it another way, the big political decision - namely how much control of our economy we are prepared to permanently delegate to the EU in return for improved access to the EU's huge marketplace - is yet to be taken.

Both the big rows, and the minutiae of fiendishly complicated trade negotiations, is yet to happen (gawd help us).

This isn't quite a blind Brexit, but it is a pretty severely myopic one.

Which confirms that Labour will vote against it.

But what about the more important opposition to the deal, from the Brexiter members of the PM's own party.

Well the PM can in fairness say to them that they wanted a Canada-plus deal for the UK and she's given them an option on that.

Tory MPs who have publicly confirmed they have written to the chairman of the Conservative backbench 1922 Committee to trigger a vote of no confidence. Credit: PA

Secondly, after Iain Duncan Smith and Owen Paterson nagged her, she has filled the PD with stuff that has no business being there, about how "facilitative arrangements and technologies will...be considered in developing any alternative arrangements for ensuring the absence of a hard border on the island of Ireland on a permanent footing".

In plain English, this means that during the 21 months of the UK's status as a non-voting member of the EU "in transition", the UK would attempt to prove that the border between Northern Ireland and the Republic could be kept open by deploying clever IT and screening kit, with some smart admin, rather than deploying the so-called backstop seen by Northern Ireland's DUP as driving a regulatory wedge between NI and ROI.

May even thanked Duncan Smith and Paterson for their lobbying efforts in this respect - which was code for "please now vote for my deal and try to persuade your recalcitrant colleagues to do the same".

But in a humiliating moment for May in the Commons this afternoon, Duncan Smith and Paterson said thanks but no thanks. They will never support her deal for as long as the backstop is in the Withdrawal Agreement.

MP Duncan Smith. Credit: PA

So will Tory Brexiters and the DUP now cease their carping, put up the white flag and rejoice that May is reborn as glorious Britannia of Brexit?

Hmmm. Stranger things have happened but that seems as likely as me receiving a call up for the England football team.

The DUP will not be able to support a Brexit deal that includes a legally binding backstop that they see as potentially putting up a barrier between NI and GB, when the intention in the PD to avoid the backstop has no legal force - as Nigel Dodds, leader of the DUP's 10 MPs, made clear on my show last night.

The number of Tory rebels will shrink, doubtless. But a core will never be persuaded to back May's deal, for reasons similar to the DUP's reservations - though their fear is less about fragmenting of the EU, and more about the possibility that the UK will remain in transition for another couple of year and then in the customs union via the backstop forever after, thus depriving the UK parliament of the control of the UK economy they seek.

Which means when the Commons votes on this, May is set to lose.

The uncertainty is quite how big she loses - because it is the magnitude of that defeat that will determine whether something like her deal is eventually Britain's Brexit or whether it will be ripped to shreds.