The National:

IF there is a legal battle between Holyrood and Westminster on the second independence referendum we already have a general map if not a specific blueprint on what would happen.

In part last week’s hearings in the Supreme Court on the United Nations Convention on the Rights of the Child (Incorporation) (Scotland) Bill also provide us with a dress rehearsal. The proposed law was passed by Holyrood in March this provoked the UK Government to ask the Justices of the Court to rule on whether the proposed legislation interfered with matters “reserved” to London under the Scotland Act 1998. The law which gave birth to our Parliament in its new incarnation over twenty years ago.

This procedure of accessing the Court to challenge Scottish legislation by the UK Government is in-built into the devolution settlement but prior to last week’s actions had only ever been used once before over the protracted Brexit battles and the Scottish Parliament’s Continuity Bill of 2018.

This map tells us where the indyref2 Bill is likely to end up if Boris Johnson’s government choose to invoke the same procedure.

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There are potential hurdles to it even making it that far. Notably the new Lord Advocate would have to give her legal blessing on the proposal before it was entered into Parliament by the Scottish Government. James Wolffe QC now retired from the position made no pronouncement at all on the prospects of the legality of a Referendum Bill when in office despite it being a constant and high profile issue in Scottish society.

The new Presiding Officer Alison Johnstone could also object if her office declares the idea to be outwith the powers of the Parliament. Though the experience of the Brexit Continuity Bill – ruled to be ultra vires by the last Presiding Officer – shows this is no obstacle to the law being debated and voted on.

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However the potential future battlefields have largely focused on the Supreme Court ruling on whether Holyrood has the power to pass a law on the independence referendum without a section 30 order temporarily transferring the “reserved” power from Westminster to Edinburgh. That is the legal model that was used in 2014 and still the stated preferred option of Nicola Sturgeon’s administration.

There has never been a legal ruling on whether this is definitively the section 30 route is the only one that can be used by Holyrood so the case that an indyref could be called by the Scottish Parliament itself is there to be argued.

You could make a case to argue that one of the reasons that the UK has raised the other legal actions challenging Scottish legislation is to make the process more “normal”. So the propaganda line of an English based court striking down our laws as an unprecedented and unusual act becomes blunted. The Welsh Parliament has dealt with several more legal challenges to its law than Holyrood.

The Supreme Court President is also a Scots Lawyer - Lord Reed – who gained a degree of publicity with his legal dissection of the Scottish Government’s arguments on the Children’s Rights Bill last week. A fact which one would assume would be highlighted by the UK Government if the Court ruled against a Referendum Bill.

One other route of legal challenge that is often downplayed need not involve the UK Government at all. The Bill could be passed by Holyrood and given Royal Assent by the Queen become a full Act of Parliament and then be challenged in the Scottish Courts by any individual or campaigning group.

This has been done several times in the last two decades, memorably with the Named Persons law which was set aside after being challenged by the Christian Institute. Although most other challenges to Scottish statute have been unsuccessful.

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Any organisation created by a legal document – like our Scottish Parliament – has limits to its power. In general we give the power to the law courts to determine where we draw the line on powers. A devolved settlement as currently exists relies on limitations as power is shared (and ultimately legally set) by Westminster.

That does not make the intervention of the Courts – either the Supreme Court of London or the Scottish institutions – any less politically damaging though. The UK Government would be advised to tread carefully even with a map, not an approach often adopted by Boris Johnson.

Dr Nick McKerrell is a senior lecturer in law at Glasgow Caledonian University