Lord Advocate intervenes in Brexit case
The Scottish government's top law officer has argued that Holyrood should be consulted before the UK can begin the formal process of leaving the EU.
The Lord Advocate, James Wolffe, was addressing the Supreme Court as it considers the historic Brexit legal challenge for a third day.
He said devolved administrations were affected by Brexit and should be given a voice before Article 50 is triggered.
His UK government counterpart argued on Tuesday that it was not necessary.
The UK government wants to start the process for leaving the European Union by using existing ministerial powers - the royal prerogative.
It is appealing against a High Court ruling that MPs must be given a vote before Article 50 can be invoked.
The Lord Advocate was given permission to intervene in the case on behalf of the Scottish government, which believes that the distinct Scottish legal system and constitutional traditions mean it is important that the country has a say.
The Scottish government accepts that Holyrood does not have a veto over Brexit, but believes there is a convention enshrined in the most recent Scotland Act in terms of legislative consent.
Mr Wolffe told the court that leaving the European Union would bring about "significant change on the legislative competence of the Scottish parliament and the legislative competence of the Scottish government".
He said: "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."
'Law of the land'
The Lord Advocate based part of his argument on the "Sewel convention" of legislative consent, which was later included in the Scotland Act and sets out where Holyrood should be consulted on legislation affecting devolved areas.
The judges questioned whether the convention could be applied as a legal requirement.
The Lord Advocate argued that Sewel is put down in legislation as "part of the law of the land" and should be respected.
The judges also questioned whether the Sewel convention had any impact on the issue before the court, but Mr Wolffe insisted it entitled the devolved administrations to have a voice.
He will continue his submission on Thursday morning.
Addressing the Supreme Court on Tuesday, the UK government's Attorney General for Scotland, Lord Keen, said the Scottish government's case was "fatally undermined" by the fact it does not have powers over foreign affairs.
Lord Keen also said it was "perfectly clear" that the royal prerogative applies in Scotland, Wales and Northern Ireland as well as England and its use is a matter for the UK government.
With specific reference to Scotland, he said: "There appears to be clear legal authority for the proposition that there is no material distinction between the foreign affairs prerogative as between Scotland and England."
He added: "All foreign relations and foreign affairs, in particular all our relationships with the EU, are not within the competence of the devolved legislators.
"There is no means by which you can suggest the exercise of the foreign affairs prerogative is in any way impinged or qualified by devolution legislation."
The Welsh government and the Attorney General for Northern Ireland have also intervened in the case, with the Supreme Court judges expected to deliver its verdict in January.