THE Lord Advocate of Scotland yesterday told the Supreme Court that the Scottish Parliament has the right under law to have a say in the triggering of Article 50 for the UK to leave the European Union.

James Wolffe QC was addressing the court on the issues surrounding the UK Government’s legal appeal that it can trigger Article 50 and Brexit without a vote in parliament, an action the High Court has declared unlawful.

The Lord Advocate started with the point that the Claim of Right Act 1689 and the Act of Union of 1707 had given the UK Parliament and not the Crown the “power to change the laws in use in Scotland”.

He then went on to address the question of whether the Sewel Convention “that Westminster would not normally legislate with regard to devolved matters in Scotland without the consent of the Scottish Parliament” applies in the current case.

Calling the convention “legislative consent” he said that Article 50 would mean “significant change on the legislative competence of the Scottish Parliament and the legislative competence of the Scottish Government”.

He added: “The executive’s [UK Government’s] claim in this case not only misconceives the respective roles of Parliament and the Crown in relation to the law of the land, but would elide the constitution, the mechanism through which the question of whether the devolved legislatures, which have power to change the law of the land, consent or do not consent to legislation.

“The approach that the UK Government is taking here elides not only the proper role of the UK Parliament, but, I say, of all the representative legislatives of the United Kingdom whose interests are in our constitution protected through the legislative consent.”

He later added: “Ultimately, the approach I invite the court to take reflects the proper institutional roles of the UK Parliament and the Scottish Parliament, in a context where the Scottish Parliament has wide legislative competence and the effect of withdrawal from EU would be significant with regard to devolved matters.

“In that context it is constitutionally relevant and significant to know whether the Scottish Parliament consents to those effects. It is then for the UK Parliament to decide, in light of the views of the devolved administration, to decide what to do.”

After questioning from the judges on the legal status of the Sewel Convention, the Lord Advocate pointed out that it was “the law of the land”.

He said there was “a context where we have four legislatures which can change the law of the land, we have a structure of constitutional convention which entitles those legislatures to have a voice in the decision”.

Questioned by Lord Mance on triggering Article 50, the Lord Advocate stated: “The United Kingdom has to make that decision in accordance with its constitutional requirements. I say that those constitutional requirements include an act of parliament.”

Lord Mance interjected: “And legislative consent.”

The Lord Advocate replied: “And the legislative consent.”

Earlier the court heard from Ronan Lavery QC, for Northern Ireland victims’ campaigner Raymond McCord, that since the Good Friday Agreement and referendum of 1998 it had been for the people of Northern Ireland to decide their constitutional future, and that there could be no change without their consent.

He argued: “It would be very disturbing for the people of Northern Ireland that the terms so agreed in the Good Friday Agreement were not binding to some extent and did not have a constitutional status.”

Dominic Chambers QC, representing Deir Tozetti Dos Santos, a hairdresser who has dual citizenship, told the judges that no body or bodies exist that can declare void legislation enacted by parliament without the authorisation of parliament.

He said no such authorisation exists and added: “The doctrine of parliamentary sovereignty is not a general principle, it is the fundamental constitutional principle upon which our legal system stands.”

That point had been taken up earlier by Lord Pannick QC, acting for businesswoman Gina Miller, who led the challenge to the use of the Royal Prerogative to trigger Article 50.

He said: “For the court to infer matters that are not in the [2015 Referendum] Act when they are matters of constitutional importance would be wrong.

“There is no language in the 2015 Act which comes close to supporting the contention which is being put forward by [the Government].”