As we rapidly approach the final showdown on the Withdrawal Agreement, it’s worth recalling what the problem with the backstop is. At a visceral level, it really is about how we see our country. Are we going to keep the United Kingdom together? And what sort of trading country do we want to be once we leave the EU? The United Kingdom as a whole gave notice under Article 50 that it was leaving the EU. That’s how it has to be under EU law: only states can be members. The EU has no legal basis at all, under the Treaties, for requiring that one part of the departing state be treated differently from the rest. Yet we have acceded in that requirement without demur and the Withdrawal Agreement provides that Northern Ireland will be treated differently from the rest of the United Kingdom. Some say that this is because the Good Friday Agreement demands a different treatment and that it “trumps” the UK’s legal right to leave the EU under Article 50. I have given my own views on the core issues in Ireland here. Our Government could have argued that there was hardly a word about borders and trade in the Good Friday Agreement and that it could be made perfectly consistent with our departure from the EU. The Government could have pointed out that, when Ireland ratified the creation of Article 50 in the Lisbon Treaty, it entered no reservation or objection that it might be inconsistent with the Good Friday Agreement – perhaps because it isn’t. As far as I know, these arguments were never made: we accepted that Northern Ireland had to be treated differently. Now Northern Ireland is indeed different in one important respect and that is that its constitutional status within the UK is subject to the Good Friday Agreement, an international treaty that both recognises that it is fully part of the UK and makes provision for it to leave the UK and become part of the Republic, subject to a separate referendum in the two parts of the island of Ireland. In effect that provides the people of Northern Ireland with a guarantee of no constitutional change without their consent. It also means, as the Irish Taoiseach said at the time, that the decision on Irish re-unification is no longer one for the British government. I have no doubt that the British government will and must adhere to that binding commitment. But we should bear in mind that it has two elements: the people of Ireland will decide if there is to be constitutional change; and the people of Northern Ireland have a veto on it, solemnly, through a referendum. The Withdrawal Agreement is heavy with declarations that it does not involve constitutional change in Northern Ireland. But this is like a burglar leaving a note in your ransacked sitting-room to say that he hasn’t burgled you. It doesn’t make it any less of a burglary. And the fact is that major constitutional change is being imposed on Northern Ireland with only opinion poll evidence that the change is acceptable. The people of Northern Ireland get no say and all but one (Lady Hermon MP) of their only functioning elected representatives are opposed. And the constitutional change being imposed on them is significant. They will, under the backstop, be subject to the direct effect of EU law with no representation and a border will be erected in the Irish Sea going way beyond the plant and animal health checks that currently operate, putting Northern Ireland firmly in the EU’s economic sphere and outside that of the UK. We will not therefore be leaving the EU together, as a single country, as we are entitled to do under international law, but in two broken bits, Northern Ireland and Great Britain. But this backstop may never come into effect, surely. And the EU assures us it is temporary (but they won’t re-open the text to commit to that) while we sort out our future relationship. In fact no: the backstop as drafted is effectively permanent and it determines everything about the future relationship. That is because the Withdrawal Agreement is explicit that the Irish Protocol stays fully in place “unless and until” it is replaced. Replacement is contemplated of course, in the form of a new trading relationship between the EU and the UK, but that new relationship will require assent from all EU member states, including Ireland. So imagine if Ireland said, as is very likely, that they wanted the special economic status that Northern Ireland has in the backstop rolled over into the new trading relationship. Without that they’d veto the future trade deal. The UK could say no, and do without a formal trade deal. But then the backstop would remain in force, because it wouldn’t have been replaced. So if we agree to the demand, Northern Ireland retains its special status. And if we say no, Northern Ireland retains its special status. It’s the perfect EU snooker. Who would sign that? So much for keeping the United Kingdom entire. But how does the backstop determine our future trading relationship, not merely with the EU, but with the world? The impulse to maintain the Union is strong in the Conservative Party and not at all absent in other parties represented at Westminster. Mrs May and her team clearly decided at some stage that the economic severance between Northern Ireland and Great Britain would be too stark if the backstop kept the former in the EU economic sphere while the latter became an independent trading entity able to strike its own deals around the world: the full panoply of EU border controls at Larne, on UK sovereign territory, wouldn’t look good. So she persuaded the EU, somewhat against their will, that in the period when the backstop applied, Great Britain too would have a special status: not quite as fully under EU law as Northern Ireland, but in a basic customs union. Confusingly (and the confusion may have been deliberate) she dubbed this proposal the “backstop to the backstop”, later shortened to “backstop”. So when the Government uses the word, it can mean one of two things or both, as the mood takes them. And it is probably true that many Conservative MPs, when they object to the “backstop”, are more fussed about this separate relationship between the EU and Great Britain than they are about the special status imposed on Northern Ireland. This basic customs union for Great Britain is, in the eyes of the EU, definitely temporary: it was a concession they never wanted to grant. Both they and the UK expect to see it replaced in the future relationship. But with what? It could in theory be with a Free Trade Agreement modelled on that signed by Canada. The EU has offered this (though it wouldn’t include Northern Ireland). It could be a much closer and subordinate relationship, similar to that between Norway and the EU. It could be as distant an economic relationship as that enjoyed by Moldova. In fact the EU has a whole suite of off-the-shelf models from which it has been inviting us to select for the last year. The Government has declined to make that selection, partly because to choose is to divide your own followers, but also because selecting a point on the spectrum between “close and subordinate” and “distant but free” exposes the fundamental sacrifice of UK sovereignty in Northern Ireland. The Government accepted early, and certainly by December 2017, that the decision as to what constituted a “hard border” in Ireland would be made by the EU and has spent the time since trying to pretend that this doesn’t oblige the UK as a whole to choose between maintaining its economic integrity and having an independent trade policy. That is the nub of the obfuscation and mistrust in which the Government has covered itself. But behind the smoke, the Government, in agreement with the EU, has set a direction for the future relationship that resolves that choice at some mid-point between the two extremes. The special status of Northern Ireland, in the EU Customs Union and in large parts of the Single Market, will be set forever if we sign the Withdrawal Agreement. And to disguise the severance that creates in the economic integrity and sovereignty of the United Kingdom, Great Britain will enter some form of permanent Customs Union, shorn of any substantive ability to make trade deals and willingly subject to a broad array of EU law and regulation with no say. This is not Brexit. Disruptive though it may be, we cannot go ahead from this point. We cannot sign the deal as it stands. The Irish backstop must go, or be rendered time-limited or terminable at the sole discretion of the British government. If the Attorney General cannot negotiate text (with the same legal status as the Withdrawal Agreement itself) that achieves one of those outcomes, then we need to take another path. That can only be fulfilling our obligations to British democracy and leaving with No Deal.