A judicial review raised by members of the Scottish, UK and European Parliaments sought clarification on whether and how the UK’s notification to leave the EU under article 50 of the Treaty on the Functioning of the European Union (TFEU) could be “unilaterally revoked” before the two-year “Brexit” deadline on 29 March 2019, with the effect that the UK would remain in the EU.

At first instance, a judge declined the petitioners’ request to refer the issue to the CJEU for advice on European law, but three appeal judges have now reversed that decision.

‘Hypothetical and academic’

The Lord President, Lord Carloway, sitting with Lord Menzies and Lord Drummond Young, heard that the petitioners, Andy Wightman MSP and others, were seeking a declarator specifying: “whether, when and how the notification…can unilaterally be revoked” – a legal question which could only be given by the Luxembourg-based Court of Justice.

They therefore sought a reference to the CJEU for a preliminary ruling under Article 267 of the TFEU, but the Lord Ordinary refused the petition on three grounds.

The judge held that the issue was “hypothetical” and “academic” as the UK government had stated that it did not intend to revoke the notification.

Secondly, he considered that the matter involved an “encroachment on parliamentary sovereignty” and was outwith the court’s jurisdiction.

Thirdly, the court held that the conditions for a reference had not been met, as the facts were not ascertainable and the issue was hypothetical.

‘Constitutional obligation’

However, the petitioners argued that the Lord Ordinary erred in holding that the issues were academic or hypothetical, arguing that the issue was of “great constitutional importance”, as if a decision to remain in the EU was available as a matter of EU law, the UK Parliament could pursue that option irrespective of UK government policy.

It was also submitted that the Lord Ordinary had erred in holding that the court could not provide an advisory declarator on the legality of future or contingent action.

The petitioners were not attempting to press the court into putting forward a particular interpretation or interfering with parliamentary proceedings – they only sought to ascertain whether revocation was “possible”, and in determining the issue the court would be fulfilling its “constitutional obligation to maintain the rule of law”.

Further, it was argued that parliamentary privilege could not be invoked to prevent the court from exercising its “supervisory jurisdiction”.

Finally, the petitioners submitted that the Lord Ordinary had erred in determining that the CJEU would not entertain a reference, as the Luxembourg-based court considered itself to be “in partnership with the national courts in order to ensure access to justice” and it was only in exceptional circumstances that the CJEU would decline a reference.

Responding, the Secretary of State for Exiting the EU argued that the question was not only hypothetical, but that an attempt to have the court influence the debate or vote was a “dangerous encroachment” on the sovereignty of parliament.

‘Competent and necessary’

However, the appeal judges observed that the “fundamental function” of the courts as one of the “three pillars of the state” was to provide rulings on what the law is and how it should be applied; and that the question raised by the petitioners was both practical and competent.

The court noted that, in terms of the European Union (Withdrawal) Act 2018, MPs will be required to vote on whether to ratify any agreement between the UK government and the EU Council, and that if no other proposal is proffered, a vote against ratification will result in the UK’s departure from the EU on 29 March 2019 - a date which is “looming up”.

In a written opinion with which the other judges agreed, the Lord President said: “It seems neither academic nor premature to ask whether it is legally competent to revoke the notification and thus to remain in the EU. The matter is uncertain in that it is the subject of a dispute; as this litigation perhaps demonstrates. The answer will have the effect of clarifying the options open to MPs in the lead up to what is now an inevitable vote. On that basis the petition is competent at least at the instance of an MP.

“A declarator by this court, suitably advised by the CJEU, that it is competent to revoke the notification with the effect that the UK will remain a member of the EU, does not infringe the boundaries of parliamentary privilege. A declarator of the law, of the nature sought, does not criticise or call into question anything that has been said in Parliament. It does not fetter or otherwise interfere with the options open to the legislature. It does not challenge freedom of speech in Parliament or parliamentary sovereignty.

“The court is not advising Parliament on what it must, or ought to, do. It is not otherwise seeking to influence Parliament’s direction of travel. It is merely declaring the law as part of its central function. How Parliament chooses to react to that declarator is entirely a matter for that institution.”

Lord Carloway added: “The reference in this case, which would be accompanied by a request for expedited procedure, would concern the operation of the withdrawal provisions in Article 50 of the TEU. The situation is not hypothetical or academic. Notification of withdrawal has been made. It may, in the absence of supervening events and perhaps in any event, take effect in about six months’ time.

“The court has been asked the question of ‘whether, when and how the notification … can unilaterally be revoked’ in advance of the expiry of the two year period. This can only be answered definitively by the CJEU. An answer would require to be provided before this court could grant the appropriate declarator. In these circumstances, reference to the CJEU for a preliminary ruling under Article 267 of the TFEU is ‘necessary’.”

In their draft reference to the CJEU, the judges ask: “Where, in accordance with Article 50 of the TEU, a Member State has notified the European Council of its intention to withdraw from the European Union, does EU law permit that notice to be revoked unilaterally by the notifying Member State; and, if so, subject to what conditions and with what effect relative to the Member State remaining within the EU?”

The Court of Session will consider the CJEU’s advice before issuing a final ruling.