THE SUPREME Court dashed the Scottish Government's hopes of a referendum next year after they ruled that the power to hold a vote was reserved to Westminster.

Lord Advocate Dorothy Bain's case had, in part, relied on a potential independence vote being “advisory” rather than “self-executing”.

That meant, she argued, that it would not have an automatic legal effect on the Union.

Delivering the decision on Wednesday morning, Lord Reed, the court's president, said it would have "important political consequences in relation to the Union and the United Kingdom Parliament".

He added: “Its outcome would possess the authority, in a constitution and political culture founded upon democracy, of a democratic expression of the view of the Scottish electorate.

“It would either strengthen or weaken the democratic legitimacy of the Union and of the United Kingdom Parliament’s sovereignty over Scotland, depending on which view prevailed, and would either support or undermine the democratic credentials of the independence movement.

“It is therefore clear that the proposed bill has more than a loose or consequential connection with the reserved matters of the Union of Scotland and England, and the sovereignty of the United Kingdom Parliament.”

The justices concluded that effect of the Bill could "not be confined to the holding of a referendum."

“Even if it is not self-executing, and can in that sense be described as advisory, a lawfully-held referendum is not merely an exercise in public consultation or a survey of public opinion.

“It is a democratic process held in accordance with the law which results in an expression of the view of the electorate on a specific issue of public policy on a particular occasion.”

Lord Reed said the panel of five Supreme Court justices had agreed that they did have the power to give a decision over whether the Scottish Parliament has the competence to legislate for another referendum.

He said the court accepted the argument that it was in the “public interest” for it to reach a decision over the issue.

“It is a question on which the Lord Advocate has to advise ministers. The answer to the question will have practical consequences: it will determine whether the proposed Bill is introduced into the Scottish Parliament or not.

“The question is therefore not hypothetical, academic or premature.”

During his statement, Lord Reed said they did not accept arguments made on behalf of the SNP, which intervened in the case, based on the “right to self determination” in international law.

The SNP had argued the limitations on the powers of the Scottish Parliament in the Scotland Act should be “restrictively interpreted in a way which is compatible with that right under international law” and cited rulings in the Canadian Supreme Court and the International Court of Justice.

Lord Reed said the court in the Canadian case, which concerned Quebec, held that the right to self-determination under international law only exists in situations “of former colonies, or where a people is oppressed … or where a definable group is denied meaningful access to government”.

He said: “The court found that Quebec did not meet the threshold of a colonial people or an oppressed people, nor could it be suggested that Quebecers were denied meaningful access to government to pursue their political, economic, cultural and social development.

“The same is true of Scotland and the people of Scotland.”