The Inner House of the Court of Session held that while the points of law in the appeal may well be arguable and the issues raised of great constitutional significance, granting permission to appeal would render the reference “academic”.

By interlocutor dated 21 September 2018 the court allowed a reclaiming motion against the interlocutor of the Lord Ordinary, dated 8 June 2018, which refused the petition brought by Andy Wightman MSP and a cross-party group of parliamentarians.

The court determined to make a reference to the Court of Justice of the European Union (CJEU) on the question of whether EU law permits a notice of withdrawal from the EU, which was made in accordance with Article 50 of the EU Treaty, to be revoked unilaterally.

The CJEU applied its expedited procedure to the case, with an oral hearing fixed for 27 November 2018.

The Lord President, Lord Carloway, sitting with Lord Menzies and Lord Drummond Young, were advised that the UK Supreme Court (UKSC) may be in a position to have an oral hearing, should permission be granted for leave to appeal, on either 22 or 26 November - almost immediately before the scheduled CJEU hearing.

The application for permission to appeal by the Secretary of State for Exiting the EU against the court’s interlocutor proceeded upon two grounds, namely that the court erred in rejecting the respondent’s propositions that: the question posed in the reference was academic or hypothetical; and answering the question posed constituted a breach of parliamentary privilege.

The judges observed that application was largely “a rehearsal of the points made in the reclaiming motion” and statements explaining the nature of the disagreement which the respondent has with the court’s reasoning.

The respondent argued that the court’s decisions were not merely interlocutory and that, if permission were not granted, he would not be able to challenge the court’s decision on parliamentary privilege in advance of the prospective vote in Parliament.

In terms of the European Union (Withdrawal) Act 2018, that vote is likely to take place, at the latest, early in the New Year.

The court’s decision, it was added, effectively enabled private individuals to raise matters relating to the functioning of the EU, with the CJEU, in circumstances when member states could not do so.

The petitioners resisted the motion by maintaining that the appeal did not involve an arguable point of law, nor one of general public importance.

It was submitted that the test in relation to academic or hypothetical questions was clear, and the court had simply applied that test in the particular circumstances.

In so far as it related to the scope of the jurisdiction of this court, that was not a matter for the UKSC to determine.

It was argued that there was no reason for the UKSC to consider the issue of parliamentary privilege at this stage, as the matter could be appealed once that had been determined, following upon receipt of the answer to the reference.

The petition, which had been made to the national court, and the subsequent reference accorded with the structure of EU law and its institutions, and denial of the ability to make the reference would have been a “breach of the duty of sincere cooperation”.

For the interested parties, it was said that the statutory test had not been met and, in particular, that there was “no single compelling reason” advanced as to why permission should be granted, adding that there was “no fundamental dispute on the law”.

It was submitted that the respondent had not dealt with the reasons given by the court on the question of whether the issue was hypothetical or academic.

It was also argued that there had been “no encroachment on parliamentary privilege” and that it was “legitimate” for this court to seek the assistance of the CJEU on the point of EU law which had been referred.

In a written statement of reasons, the Lord President said: “The points of law in this appeal may well be arguable and the matters raised are of great constitutional significance. However, if permission were granted, and the CJEU were thereby required to await the decision of the UKSC, then even if the UKSC were able to hear the case on the dates provisionally fixed, there would seem to be little prospect of the CJEU being able to answer the question in the reference in advance of the prospective parliamentary vote.

“It has to be assumed that, whatever the date of the oral hearing, the UKSC would require some time to consider the points raised. Permission would, in short, render the reference, and indeed the petition, academic. For this reason, permission to appeal must be refused.”

Lord Carloway added: “As permission is thus refused, if the CJEU answer (or decline to answer) the reference, the first ground of appeal will be resolved in terms of EU law at least. Depending upon the answer, and the circumstances then prevailing, whether the question raised in the petition is academic will be capable of being answered in the petition process. The normal route of appeal will then be open in relation to any matters remaining to be determined by the court.

“Whether this court’s decision amounts to a breach of parliamentary privilege will be capable of being the subject of an application for permission to appeal once this court’s procedures have been exhausted. The court does not consider that its decision in any way fetters the options open to Parliament or freedom of speech within its walls. If it transpires that it has done so, that question would be better answered, after due consideration, then rather than now.”