Last Friday, the Lord Advocate published the Scottish Government's intervention in the ongoing Brexit litigation before the UK Supreme Court . James Wolffe QC weighed in behind the Divisional Court's judgment, arguing that the royal prerogative cannot lawfully be used to trigger Article 50. But Scotland's senior law officer also ranged beyond that. He points to the Sewel convention , arguing that if Westminster legislates to withdraw the UK from the European Union, the Scottish Parliament must be consulted.





The Lord Advocate isn't arguing that Holyrood has a veto -- but that the UK constitution now expects MPs to canvas the view of MSPs before legislating on devolved matters. Modern understandings of the Sewel convention generally recognise that it has two limbs. Firstly, that Westminster ought to seek the consent of Holyrood before changing Scots law on issues falling within the Scottish Parliament's purview, like health, or education, or family law. And secondly, that any changes to the powers of the Scottish Parliament itself ought to take account of MSPs' views. The same goes for any changes to the power of Scottish Ministers, whether enhancing or curtailing their legal authority.





In a nutshell, they are that devolution is irrelevant to the issues before the Court, that foreign affairs is reserved, and that ""the devolution legislation cannot add to the arguments" in the case "in any material way." But perhaps most eye-catching, are the UK government's observations on the need to seek consent from any of the devolved legislatures. "The Court is being invited ... to stray into areas of political judgment rather than legal adjudication." They argue the Supreme Court "should resist that invitation."





So how do they reach this conclusion? While recognising that the statutes establishing Edinburgh, Belfast and Cardiff assemblies are "very significant pieces of legislation", they contend that the Sewel convention is not justiciable - which is to say, unsuitable for judicial decision-making. It is, they say, a "legal irrelevance", just a "political convention", and not part of UK constitutional law. In support of this view, they cite Lord Reed -- one of the justices who will hear this case, In 2012, in the Imperial Tobacco case, Lord Reed described the convention as a “political restriction on Parliament’s ability to amend the Scotland Act unilaterally" -- not a legal restriction.





chose in 2016 to inscribe this convention on the face of the And as far as this goes, this is a perfectly orthodox account of the status of constitutional conventions in the UK. They have generally been regarded as "rules of constitutional morality", rather than rules of constitutional law, susceptible to enforcement by the court. But where the UK government's case hits a potential wrinkle is that Westminsterin 2016to inscribe this convention on the face of the Scotland Act . They simultaneously " recognised" the "permanence" of the Scottish Parliament.





While Lord Reed was absolutely right in 2012, that the Sewel convention was only a political restriction Westminster had undertaken to abide by, this isn't straightforwardly the case in 2016. The UK government's submission - strikingly - has nothing whatever to say about this change, and the impact it might have on their arguments about the justiciability and enforceability of the convention. Back in 2014, Professor Mark Elliott tacked up this informative article about the different potential legal effects of these innovations. In its legal papers, the UK government body-swerves these implications altogether.





So does the statutory recognition of Sewel change anything? Maybe. Maybe not. As a number of us pointed out at the time, David Mundell formulated this statutory recognition in a consciously sleekit way. The new Scotland Act recognised only that "the Parliament of the United Kingdom will not normally legislate with regard to devolved matters without the consent of the Scottish Parliament." "Normally" isn't a word you encounter very often in statutes. "Must" and "may", certainly. But not "normally."







"... whether circumstances are ‘normal’ is a quintessential matter of political judgment for the Westminster Parliament and not the courts. There are no judicial standards by which to measure such a question in the context of a political convention." You didn't hear this kind of reasoning - at least in public - when UK lawyers, unsurprisingly, have hung up their wigs on these words. Referring to the Scotland Act, they suggest the convention "does not purport to prescribe an absolute rule." Its content is only that “Westminster would not normally legislate” And here is the kicker. They argue that:You didn't hear this kind of reasoning - at least in public - when David Mundell was talking up the virtues of the new Act, invoking the idea of a "new parliament, new powers, and new partnerships."





For the UK government lawyers, we end with the orthodox Diceyan vision of the tyrannical patriarch, and the erratic father figure never needs to keep his word, or follow his own rules. Whatever forms of "legal recognition" or apparent constraints Westminster inscribes on its constitutional legislation, "the Westminster Parliament is sovereign and may legislate at any time on any matter ... any attempt to enforce the convention directly or indirectly would be a straightforward impingement on that sovereignty."





Theresa May's legal counsellors may be resisting any attempt for parliament to take back control over Brexit, but they take Holyrood's subordination to Westminster for granted. For Richard Keen and his colleagues, power devolved is ultimately power retained, whatever political grace notes ministers write into the latest iteration of devolution, whatever our constitutional statutes anticipate and provide. And if the strident, haughty tone of this reply is anything to go by -- how very dare you argue otherwise.