Kenneth A. Armstrong: Will the Supreme Court Clear the Way to a Scottish Independence Referendum?

At the end of June, Scotland’s First Minister Nicola Sturgeon set out the Scottish Government’s roadmap for a referendum on Scottish independence. The centrepiece would be a Bill to be introduced into the Scottish Parliament to legislate for a referendum in like terms to the 2014 independence referendum, but absent an accompanying section 30 order giving the Scottish Parliament express competence to legislate for a referendum. In addition, Scotland’s Lord Advocate confirmed that she would be making a reference to the United Kingdom Supreme Court (‘UKSC’) for a determination of whether such a Bill, if introduced, would relate to a reserved matter. The rationale for the reference would be to provide definitive legal clarity as to the scope of the Scottish Parliament’s legislative powers.

On 23 November, the UKSC gives its response to the Lord Advocate’s request for legal clarity. In an earlier blog coinciding with the making of the Lord Advocate’s reference I speculated that the UKSC might have cause to ponder whether it had jurisdiction to entertain a reference. In advance of the UKSC’s judgment, in this post I suggest that the Lord Advocate may not get the legal clarity she seeks because the UKSC decides either to exercise a discretion to refuse the reference, or – and consistent with the scheme of the Scotland Act – it simply finds as a matter of statutory interpretation that it does not have the jurisdiction to offer advice at a pre-legislative stage.

The substantive question on whether the Scottish Parliament can legislate for an independence reference may simply be left unanswered by the UKSC.

Scrutiny of Devolved Bills

The specific jurisdiction of the UKSC in respect of Bills introduced into the Scottish Parliament is found in section 33. It is limited to pre-enactment scrutiny once the terms of a Bill have been settled – following completion of the legislative process – but before Royal Assent has been granted. What is not expressly anticipated by the legislative scheme for UKSC review is pre-legislative scrutiny of a Bill that has not yet been introduced into the Parliament where the competence of the Parliament is in question.

Rather, section 31 of the Scotland Act identifies that ‘on or before’ a Bill’s introduction, the person in charge of a Bill shall make a statement that in their view the provisions of a Bill would be within legislative competence. Such a statement may be contested by members of the Parliament or indeed by the Presiding Officer who must also state their view on whether a Bill is within legislative competence. The point of this provision is to make the competence of the Parliament to legislate on a Bill a matter of political debate. It would seem that judicial scrutiny is limited to reviewing the outcome of political deliberations on a Bill once it has been passed.

The complicating factor lies outside the Scotland Act itself and is instead to be found in the Scottish Ministerial Code. Before a minister can provide the required statement on legislative competence to accompany the Bill, the statement must be cleared by the law officers (paragraph 3.4). It is important to underline that this step does not derive from the Scotland Act itself.

The Residual Direct Reference Procedure

In the absence of more express language within the Scotland Act allowing pre-legislative judicial scrutiny of a Bill, the Lord Advocate’s contention is that the UKSC’s jurisdiction can be found in the residual direct reference provision in paragraph 34 of Schedule 6 to the Scotland Act 1998 that permits the Lord Advocate (and other UK and devolved law officers) to refer to the UKSC any ‘devolution issue’ which is not the subject of other proceedings. Paragraph 1(f) of Schedule 6 defines a devolution issue as:

Any other question about whether a function is exercisable within devolved competence or in or as regards Scotland and any other question arising by virtue of this Act about reserved matters.

It is the latter part of this provision which the Lord Advocate has sought to rely on in conjunction with paragraph 34.

The correct interpretation of the scope of this residual power will be considered below. For the moment, if we assume that the question referred could be within the scope of this power, the question arises whether, nonetheless, the UKSC might exercise a judicial discretion to refuse the reference.

The Exercise of Judicial Discretion by the UKSC

That the UKSC has a discretion to refuse a reference was apparently accepted by the Court in its February 2020 judgment refusing to accept a reference from the Attorney General for Northern Ireland. Here, the UKSC regarded the provision of district postcodes by a Northern Ireland department for the purposes of implementing welfare legislation as bringing the situation within the scope of a ‘devolution issue’ and so potentially the appropriate subject of a reference to it. However, the UKSC exercised its discretion to refuse the reference on the grounds (a) that what brought the matter within the scope of a devolution issue was not ‘centre stage’ in terms of the alleged unlawfulness that might be complained of, namely incompatibility with Convention rights and (b) the availability of other proceedings by which complaints might be raised.

The Scottish Lord Advocate’s reference affords the UKSC an opportunity to define more clearly the ambit of this discretion. It has a choice. Either it runs with this idea of judicial discretion and the policy arguments that underline its scope and exercise, or it acknowledges a more residual discretion but finds that the policy arguments that might guide that discretion to be already present in the scheme of the Act and the limited role assigned to judicial scrutiny.

If the UKSC chooses to develop the idea of a judicial discretion to refuse a reference, the point to take away from earlier cases might be that while the Lord Advocate’s reference may concern a devolution issue – for example, a ministerial statement about legislative competence – what is actually centre stage is the capacity of the Lord Advocate to offer advice as to whether a Bill to be introduced is within legislative competence. Although law officers do have access to the UKSC in ways specified in the devolution legislation, the use of this residual reference power ought not to extend to the essential function of a law officer in the giving of advice, even if that advice is about a devolution matter.

As to whether the question referred might find its way to the Supreme Court by other proceedings, this does not seem to have featured strongly in the case. An earlier attempt to engage the Scottish courts on the same question in the case of Keatings was dismissed on the grounds of raising a hypothetical question. That private plaintiffs might face difficulty in raising proceedings could support an argument that a law officer ought to be able to act in the public interest. And indeed, the integrity and professionalism of law officers may be a control on the triggering of the residual reference power that could give the UKSC some comfort in the exercise of a discretion to allow a reference where it might be unlikely that a question might be raised in other proceedings. But that might cut both ways when the essence of the reference is the ability of a law officer to perform their essential professional function – to offer advice.

Rather than simply relying on the rare examples in which a law officer reference has been refused, the UKSC could instead take the opportunity to espouse the theory and practice of judicial discretion derived from a wider body of case law encompassing other cases raising devolution issues – e.g. failed attempts by the Counsel General for Wales to obtain clarification of the impact on devolution of the United Kingdom Internal Market Act – as well as other examples where courts have exercised discretion to refuse declaratory remedies. These cases are variations on a theme in which courts consider whether an issue is premature, hypothetical, or advisory.

Access to the courts may be denied where the application has been raised prematurely in that the precise factual and legal context of the issue is not settled. A hypothetical question is one that is too abstracted from any dispute between the parties and any remedy sought. More interesting perhaps is the discretion to refuse to entertain legal proceedings because it is intended simply to provide authoritative advice on a legal question. As intimated earlier, the reference procedure under the Act does perform something of that function but where the issue is clearly live in other proceedings or because the Act makes express provision for this advisory jurisdiction. Where the central issue is the capacity of a law officer to offer advice to ministerial colleagues, it is arguably not the role of the UKSC to step into the shoes of the law officer and to enter the domain of politics. Whatever control may be exercised by way of the integrity and professionalism of law officers in requesting a reference, the response of the UKSC, it is submitted, should always be to refuse a reference that concerns the essential function of a law officer in the giving of professional advice to ministers. This may make life difficult for a law officer given that the Scottish Ministerial Code requires the Lord Advocate to ‘clear’ a ministerial statement about legislative competence. But whatever political difficulties that creates, the point remains that the difficulty arises not by virtue of the Act but by virtue of the Code and the apparent inability to introduce a Bill where a law officer cannot give a minister absolute clarity as to whether it is within legislative competence.

Whatever may be the merits of clarification by the UKSC of the scope and limits of judicial discretion, as I argue below, much of what might be framed as the policy arguments underpinning the exercise of judicial discretion may simply be inherent within the legislative scheme of the Scotland Act itself, providing the UKSC with stronger legal foundations for its response to the reference.

Does the Question Arise ‘by virtue of the Act’?

A different way of framing a judicial discretion to refuse to answer a question in which the devolution issue is not ‘centre stage’ is simply to say that in the statutory language of the residual reference power, the issue does not arise ‘by virtue of the Act’. It is clear from the Act that the person in charge of a Bill must state that in their view the Bill is within legislative competence. However, what is at the core of the reference is whether the Lord Advocate – in advising a minister with a view to clearing a statement that a Bill is within competence – is in a position to offer clear legal advice. The issue arises, therefore, both as an intrinsic function of the office of the Lord Advocate and, more precisely, in the context of the operation of the Scottish Ministerial Code. The issue does not arise by virtue of the Act as such.

This is not splitting hairs. As Chris McCorkindale so eloquently sets out in his blog on the role of the Lord Advocate, there are important interactions between ministers, MSPs, law officers and other sources of official legal counsel as a Bill makes its way through the parliamentary procedure. That there may be uncertainty as to whether this or that provision takes a Bill into reserved or protected matters is part of the political process whether or not the courts are ultimately engaged in determining such issues. Deliberation under conditions of some legal uncertainty may be said to be a design feature rather than a flaw to be corrected by giving law officers direct access to the UKSC at a pre-legislative stage.

Does the Question Relate to a Reserved Matter?

Even if the UKSC accepts that the concept of a devolution issue gives the residual reference power a wide ambit, nonetheless, the final part of Schedule 6, paragraph 1(f) requires the question to be about ‘reserved matters’. Section 29(2) of the Scotland Act tells us that the provisions of an Act that relate to reserved matters are outside of the legislative competence of the Scottish Parliament. Schedule 5 of the Act contains the familiar list of reserved matters including the union of the Kingdoms of Scotland and England and the UK Parliament which the Lord Advocate identifies as being the reserved matters for which she seeks clarity in respect of the provisions of the proposed independence referendum Bill.

At first blush one might think that the Lord Advocate’s reference clearly relates to reserved matters. But there are two ways of pushing back on this conclusion. The first is a reframing of the earlier point to say that what is at issue is not the terms of the Bill as such (and any encroachment on reserved matters) but more straightforwardly whether the Lord Advocate is in a position to discharge her function in giving legal advice. The second point provides a different way of presenting the ‘premature’ or ‘hypothetical’ points we discussed in relation to judicial discretion. In respect of ‘reserved matters’, the Scotland Act and relevant case law focuses attention on whether provisions of Acts of the Scottish Parliament or pre-enactment Bills relate to reserved matters having regard to their object and purpose e.g. the Scottish ‘Continuity Bill’ reference or the subsequent references on the Bills implementing in Scotland the UN Convention on the Rights of the Child and the European Charter of Local Self-Government. This is a question that requires close contextual statutory interpretation of settled provisions following the completion of the legislative process. To ask the UKSC to undertake this task of determining whether provisions of a pre-legislative draft Bill relate to ‘reserved matters’ is to take the UKSC beyond its jurisdiction and instead to draw it into the legislative process at its outset. The qualification that an issue relates to ‘reserved matters’ is, arguably, also limited by a presupposition that a provision can be definitively interpreted in its statutory (or pre-enactment) context. That judicial task cannot be undertaken at a pre-legislative stage.


It may be a cause of political frustration for Scotland’s First Minister – it may even provoke the resignation of the Lord Advocate – but my conclusion is that the Supreme Court ought to refuse the reference and ought to do so, not as a matter of judicial discretion, but as an interpretation of the legislative scheme of the Scotland Act and the underlying relationship between courts and politicians in the making of devolved legislation.

Kenneth A. Armstrong is Professor of European Law at the University of Cambridge.

(Suggested citation: K. A. Armstrong, ‘Will the Supreme Court Clear the Way to a Scottish Independence Referendum?’, U.K. Const. L. Blog (21st November 2022) (available at