Brexit chaos shows breaking up Unions isn't worth it '“ Brian Wilson

Last time Nicola Sturgeon tried to exploit Brexit to win Scottish independence, it cost 20 SNP MPs their seats (Picture: Jeff J Mitchell - Pool/Getty Images)

If the shrill mood music could be turned off, I wonder how outraged the nation would be about the Brexit agreement on offer? Or would it opt just to get on with it?

Alas, there is no room for such heresies. I heard David Davis rubbishing the deal he ran away from concluding, sneering at Theresa May for “rolling-over” and refusing to accept a shred of personal responsibility. That sums up what he and his cohorts have to offer.

The serious UK negotiators ended up where they were always likely to – ticking the Brexit box but keeping relationships as unchanged as possible while doors are open to future finessing, by which time both orchestra and music will have changed.

In the meantime, life would go on. Business can live with the deal. Trade would flow. Travellers would not be herded into Brexit lanes at airports. Phone calls in Marbella would not revert to costing a fortune.

Whether it’s all worth is a separate question but it’s not exactly the apocalypse. Taking rules we no longer help to make is unavoidable if we leave a club. Even that affront is more theoretical than real. British diplomacy in Brussels is unlikely to switch off on Brexit day.

In a significant nuancing, Theresa May said there are three options – her deal, no deal or stay in the EU. A “no deal” exit is such utter madness that Parliament, propelled by overwhelming public opinion, will not allow it to happen.

Nicola Sturgeon told to forget independence referendum by Theresa May's deputy

Accordingly, at some point, it will occur to all but the most fanatical Brexiteers that they can have the half-cake of leaving the EU or – by one route or another – the probability of Brexit collapsing which would render their political lives even more futile than at present.

Opposition parties are under no obligation to save the Tories from themselves so all the onus lies with Tory MPs. Regardless of leader, the choices will not change significantly. The absence of a plausible alternative from Davis and co remains the most striking feature of this whole debacle.

Personally, I could live comfortably with Mrs May’s deal, some modest variation, a General Election which would be fought on whether or not to have a second referendum or indeed the whole thing disappearing in a puff of smoke. It is the recklessness of “no deal” that must be united against.

In Scotland, we have predictable crowing that every day of chaos makes independence more certain. Reason points in exactly the opposite direction but whenever opportunism knocks, Nicola Sturgeon can be relied on to answer.

Last time round, her rush to exploit Brexit cost 20 MPs their seats. Behind the soundbites about “chaos” lies the same contradiction. Why pin one’s colours so uncritically to the mast of one Union while working day and night to break up another?

I find claims for equivalence with Northern Ireland particularly distasteful. We do not live on a partitioned island. We have not seen the folly of bloodshed. We do not have a land border. These are the circumstances which make Northern Ireland genuinely difficult. Stay clear of them.

Among the litany of lies in the 2014 White Paper, we were assured the post-referendum negotiation would take 18 months and cost next to nothing before Alex Salmond became ruler of all he surveyed. As Brexit’s complexities have confirmed, this was sheer fantasy.

Ms Sturgeon is forever demanding apologies and resignations but was any of this rubbish ever apologised for? In the interim, the love-in with Catalonian separatists surely ended whatever chance there might have been of Scotland being ushered into the EU.

So what would be their offer? Scotland outside the EU and outside whatever post-Brexit deal the UK will have settled into with the little matter of a £15 billion deficit still to be explained away? It’s not a great prospectus.

It is possible the current shambles will make Scottish voters desperate for another threat of chaos after 2021. More likely, I think, they will be even more resistant to the fiction that breaking up Unions is remotely worth the money and pain.