This week, all eleven Justices of the UK Supreme Court will hear the appeal in the matter of R (on the application of Miller & Dos Santos) v Secretary of State for Exiting the European Union [2016] EWHC 2768 (Admin) – otherwise more commonly known as “the Article 50 Brexit appeal”.

A number of interested parties have intervened in the proceedings, including the Lord Advocate (James Wolffe QC), the Scottish Government’s principal legal adviser and the senior Scottish Law Officer. The Lord Advocate sought permission to intervene because of the significance of the constitutional issues engaged in the case, and in particular, their importance for Scotland. The UK Supreme Court has granted the Lord Advocate’s application for permission to intervene and he will be heard this week.

Separately, the Advocate General for Scotland (Lord Keen of Elie QC), the UK Government’s Law Officer for Scotland, will also appear and is expected to address the Scottish position from the UK Government’s perspective.

The hearing of this appeal promises to be one of the most significant constitutional challenges of our time, with Scotland’s voice being heard on behalf of two different governments, with two very different and competing perspectives on Scotland’s future in Europe.

What is the intervention?

The appeal itself concerns the question of whether the UK Government has power under the Crown’s prerogative alone to invoke Article 50 of the Treaty on European Union.

The Scottish Government’s position is that it does not: it aligns itself with the position of the claimants, Ms Miller and others. It argues that the decision to withdraw from the EU requires an Act of Parliament and that the UK Government cannot act alone, without parliamentary approval.

Moreover, the Lord Advocate will argue that withdrawal from the EU would result in changes of law that fall within the devolved competence of the Scottish Ministers under the Scotland Act 1998. Accordingly, the Lord Advocate will argue that any Bill brought before the UK Parliament would engage the constitutional Sewel convention, which provides that the UK Parliament does not normally legislate in devolved matters, without the consent of the Scottish Parliament.

With 62% of voters in Scotland voting to remain in the EU in the June 2016 referendum, the Scottish Parliament would be expected to refuse that consent. Even if consent were refused, the UK Parliament could still pass the legislation required, but to ignore a refusal of consent from the Scottish Parliament could have significant constitutional and political consequences for the future of the Union. The big question next week for watchers of the UK constitutional settlement will therefore be: could Scotland block Brexit?

Timings of the Scottish submissions

On behalf of the UK Government, Advocate General for Scotland Lord Keen of Elie QC is expected to make his submissions late this afternoon (Monday 5 December 2016) and early tomorrow morning (Tuesday 6 December 2016).

On behalf of the Scottish Government, the Lord Advocate James Wolffe QC is expected to make his submissions on the afternoon of Wednesday 7 December 2016 and the morning of Thursday 8 December 2016.

Follow the case this week

As the UK Supreme Court tackles these significant constitutional issues this week, there will be many opportunities to engage with the proceedings.

The UK Supreme Court is streaming the proceedings live here: