(https://thecritic.co.uk/issues/april-2021/how-to-scotch-independence/)

If the Scottish National Party does well enough in the elections on 6 May, the UK Supreme Court may soon become the focus of public attention once again. At stake will be nothing less than the future of the United Kingdom. The SNP is committed to holding a second referendum on independence for Scotland. The 2014 vote — which rejected independence by 55 to 45 per cent — had the blessing of the UK government. This one will not.

Unlike its Westminster progenitor, the Scottish parliament has limited powers. Any act of the Scottish parliament that “relates to” the “Union of the Kingdoms of Scotland and England” is outside its legislative competence. That’s one of a number of matters that were reserved to UK legislators by the Scotland Act 1998.

How, then, was an independence referendum possible? Section 30 of the act allows the Westminster government to modify reserved functions. Ministers simply made a temporary order allowing Scotland to vote in 2014. Well, say the SNP, we’d like another of those section 30 orders, please. And if Boris Johnson refuses? We’ll pass the legislation anyway — and dare you to challenge it.

That’s where the Supreme Court comes in. Whenever the Scottish parliament passes legislation, the attorney general has four weeks to ask the court whether it was within the legislature’s competence. The Supremes are surely bound to conclude that — in the absence of a section 30 order — Scottish legislation authorising an independence referendum is of no effect.