“The clock is no longer ticking” announced Michel Barnier at the Brussels press conference that confirmed that the largest trade deal Britain and the EU have ever concluded has been agreed between them.

And when, next week, it is ratified by the Houses of Parliament and provisionally by the member states of the European Council, its supporters will hope it has called time on the protracted debate about the future relationship between the UK ad EU.

A “no deal” would have kept that timepiece ticking. And if the detail of the agreement proves far more injurious to Britain’s room for manoeuvre than Boris Johnson’s bold suggestion that it is effectively the Canada deal he always claimed to want, then the prime minister’s dislocation from a significant section of his parliamentary party – and a of the electorate – will worsen.

But even a large backbench rebellion will not prevent this deal from becoming law. Indeed, Keir Starmer’s decision to support it does more than make its parliamentary passage a racing certainty – it kills Brexit as a dividing issue for the two main Westminster parties for the remainder of this parliament and probably far beyond.

Having been one of the architects of the second referendum strategy, Starmer has learned from the electoral catastrophe he played his part in creating. What good would it do Labour at the next election to say it wants to reopen negotiations with Brussels when most voters, frankly tired of the whole business, will remember not the detail of what was reached on Christmas Eve 2020 but the headline that Boris Johnson said he would get Brexit done and – after a fashion – did so.

Normally, no event in British politics however large or small can happen without the Liberal Democrats’ almost instantly issuing a press release condemning it and demanding the “government must act.” Strangely on a subject so close to its heart, the Liberal Democrats have been silent this day. It is not easy for them. For what are they to say – that they welcome the deal but wish the government had conceded to Brussels’s demands quicker and more abjectly? And if this deal is considered good enough in Brussels, are the Lib Dems to feel it still is not European enough for them? There is niche appeal for that.

So, it will be for the SNP to keep the grievance alive in Scotland and, in the process, to destabilise the rest of the UK as best it can. Beyond Scotland, even diehard Remainers should ask themselves whether they ought to wish the Scottish Nationalists well in that provocation.

if the Brexit Party thinks that the deal is just about tolerable, it would be beyond remarkable for the majority of Conservative MPs to decide otherwise

All these instant party responses come when there is only spin and guidance to go on, not to the primary materials. That Britain’s leading news services still cannot agree on whether the agreement runs to one thousand or two thousand pages gives some sense of how little anyone outside the direct negotiations knows about the new rules governing our relationship. Until the text is open to scrutiny – not least by the European Research Group’s ‘star chamber’ of legal experts chaired by Sir Bill Cash, which did so much to discredit Thresa May’s deal – the scale of a Tory backbench rebellion cannot be measured.

But if the Brexit Party (which, tellingly, is trying to rebrand as Reform UK) thinks that the deal is just about tolerable, it would be beyond remarkable for the majority of Conservative MPs to decide otherwise.

In a statement released shortly after the agreement was announced, the Brexit Party’s chairman, Richard Tice, conceded, “this deal is in no way perfect and it must be checked in detail. It seems, at first glance, satisfactory in getting our freedom on security, defence and foreign policy, and, most importantly, free of the superiority of the European Court of Justice. There are clearly some compromises on the level playing field and fishing which will have to play out and be kept under close review. However, right now this is as good as we are going to get.”

This is not the language of “a nation betrayed.”

The post-announcement press conferences were hardly revelatory. A briefing from Boris Johnson is never going to satisfy those focused on detail. The press conference in Brussels was scarcely more forensic.

But something said by the European Commission’s president, Ursula von der Leyen, emphasised why Brexit has happened and why it will not be easily reversed even if as a result of this agreement it can be constrained.

“We should cut through the soundbites and ask ourselves what sovereignty actually means in the twenty-first century,” von der Leyen suggested. “For me, it is about being able to seamlessly do work, travel, study and do business in 27 countries. It is about pooling our strength and speaking together in a world full of great powers.”

These may be objectives that bring benefits and have value in themselves. But as an interpretation of the meaning of sovereignty it is not one that chimes with British ideas of accountable governance. That, constitutional, concept of sovereignty is not a “soundbite” to be cut through. And if the European Commission thinks that it is, then, to resurrect the wisdom of Winston Churchill, perhaps a future in which Britain “is linked but not combined” to Europe really is best for all concerned.