REALISTICALLY, there are only three options available to the UK Supreme Court, which this week is hearing argument in the case brought to it by the Scottish Government, that Holyrood ought to be permitted to hold a repeat referendum on independence even without Westminster’s consent.

None of the options favours the nationalists. Whatever you read about the law and politics of Indyref2 this week, know this: it is not going to happen. Not anytime soon. And certainly not on the fanciful timetable Nicola Sturgeon says she prefers.

The first option available to the court is they rule this week’s case out as being premature. Rather ingeniously, the Scottish Government’s Lord Advocate has bypassed and short-circuited the normal legal procedures used for testing whether Holyrood’s enactments are within its law-making competence. Those processes can be triggered only after the Scottish Parliament has debated and passed a bill into law.

As things stand, no such bill has even been introduced into Holyrood, never mind debated, amended, or passed. And yet here we are in court already. It is open to the justices to rule that the case should have come nowhere near the Supreme Court until after Holyrood has enacted a bill – then, and only then, could any binding ruling be made as to that bill’s legality. That’s option 1.

Option 2 is for the court to accept that it should rule on the substance, despite the unusual route the case has taken to get into court. The substance of the matter is as follows: Holyrood will have the lawful authority to enact a law authorising a second independence referendum without Westminster’s consent only if that law does not “relate to” reserved matters. The Union of Scotland and England is a reserved matter. Clearly, independence itself relates to the Union (it would relate to the Union by terminating it). But does a bill which authorises not independence itself but a referendum about independence relate to the reserved matter of the Union?

The legal tests the court must deploy to answer this question are set out in the Scotland Act – whether a measure relates to reserved matters depends on its purpose, having regard to its effect in all the circumstances. Thus, there are two relevant tests –purpose and effect. Option 2 is for the justices to rule as the UK Government would like them to rule: namely, that the purpose of an independence referendum is to prosecute the case for independence (which relates to the reserved matter of the Union) and that the effect of an independence referendum is to determine whether the Union continues or not.

Thus, both the purpose and the effect of an independence referendum relate to a matter – the Union – which the Scotland Act reserves to Westminster. And, as such, Holyrood has no legislative competence to enact an Independence Referendum Bill into law without Westminster’s consent. That’s option 2.

Option 3 is more subtle. But, even if this is the option which the justices in the end take, the nationalists still lose. Option 3 goes back to those key tests of purpose and effect and probes them more deeply. In her written case to the court, the Lord Advocate has accepted that the purpose of any independence referendum cannot be to secure independence. Independence itself would require its own legislation – lots of it, in fact – in both Holyrood and Westminster.

In this respect, independence is just like Brexit. Brexit was not secured by the 2016 referendum. It was secured, only years later, by legislation enacted by Parliament and by agreement with the European Union, agreement which took years of wrangling to deliver.

Thus, concedes the Lord Advocate, the purpose of an independence referendum bill is simply to test the opinion of the people of Scotland – and this purpose (testing public opinion) is not reserved to Westminster. Likewise, she concedes that the effect even of a Yes vote cannot of itself amount to anything in law. Again, just as with Brexit, the mere expression of public opinion in favour of leaving changes nothing.

Option 3, then, is that the Scottish Parliament can hold Indyref2 without Westminster’s consent, but only on the understanding that the purpose of the referendum is simply to ask voters to express a preference (as they would, for example, in an opinion poll) and that the effect of so doing is, precisely, “nil” (to use the Lord Advocate’s memorable word).

Were such a referendum to take place, it would be so hollowed out of meaning it would amount to nothing more than an empty stunt. Those opposed to it would simply ignore it, refusing to have anything to do with it. There would be no No campaign. The Unionist parties (and their supporters) would boycott the whole thing, and the SNP would look ridiculous.

And that’s it. Those really are the only three options the Supreme Court has in deciding this case. I have no more idea than anyone else which option – or which combination of options – the justices will choose. But, whatever happens, the nationalists lose.

Which leaves only one question, really: given that the nationalists must know all of this, why have they brought the case to the Supreme Court in the first place? They cannot win from here, so why do it? Perhaps it is all just an act, designed to buy time. Nicola Sturgeon has become rather experienced at pulling the wool over her supporters’ eyes, making them believe that a referendum is just around the corner when she knows full well it is not.

One day, perhaps they will realise that – for years, now – they have been taken for a ride.

Adam Tomkins was a Conservative MSP for the Glasgow region from 2016 to 2021.

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