1. The background to the reference

4. First, the background to the reference should be briefly explained. The Scottish National Party, which is committed to Scottish independence, has formed the Scottish Government since 2007.

5. In 2013 an Order in Council was made under section 30(2) of the Scotland Act so as to enable the Scottish Parliament to legislate for the holding of a referendum on independence. The Order in Council did so by modifying the definition of reserved matters in Schedule 5 to the Scotland Act. In particular, paragraph 1 of Schedule 5 provides:

1. (a) the Crown, including succession to the Crown and a regency,

2. (b) the Union of the Kingdoms of Scotland and England,

3. (c) the Parliament of the United Kingdom,

4. (d) the continued existence of the High Court of Justiciary as a criminal court of first instance and of appeal,

5. (e) the continued existence of the Court of Session as a civil court of first instance and of appeal.”

The Order in Council inserted a new paragraph 5A into Schedule 5, which provided that paragraph 1 did not reserve a referendum on the independence of Scotland from the rest of the United Kingdom if specified requirements were met. Paragraph 5A is no longer in force.

6. The referendum authorised by the Order in Council was held in 2014, and resulted in a majority vote against independence.

7. The Scottish Government wishes to hold another referendum on independence. The United Kingdom Government is unwilling to agree to the making of a further Order in Council under section 30(2) at the present time. In those circumstances, the Scottish Government wishes, if possible, to hold a referendum without an Order in Council, and therefore without any modification of the definition of reserved matters in Schedule 5.

8. Absent legislation by the United Kingdom Parliament, the holding of a referendum requires authorisation by an Act of the Scottish Parliament. The power of the Scottish Parliament to make legislation, described in the Scotland Act as its “legislative competence”, is limited. Section 29(1) of the Scotland Act provides that an Act of the Scottish Parliament is not law so far as any provision of the Act is outside the legislative competence of the Parliament. Section 29(2) lists five circumstances in which a provision is outside legislative competence:

1. “(a) it would form part of the law of a country or territory other than Scotland, or confer or remove functions exercisable otherwise than in or as regards Scotland,

2. (b) it relates to reserved matters,

3. (c) it is in breach of the restrictions in Schedule 4,

4. (d) it is incompatible with any of the Convention rights or in breach of the restriction in section 30A(1),

5. (e) it would remove the Lord Advocate from his position as head of the systems of criminal prosecution and investigation of deaths in Scotland.”

In relation to section 29(2)(b), as was explained earlier, reserved matters are defined in Schedule 5. Paragraph 1(b) and (c) of that Schedule reserve “the Union of the Kingdoms of Scotland and England” and “the Parliament of the United Kingdom” respectively: see para 5 above. If legislation authorising the holding of a referendum would relate to either or both of those matters, it would accordingly relate to a reserved matter, and be outside the legislative competence of the Scottish Parliament.

9. Sections 31 to 33 of the Scotland Act provide for the scrutiny of Bills in order to check that they are within legislative competence. It will be necessary to consider these provisions in some detail. For present purposes, it is sufficient to note the terms of section 31(1):

In the case of a Bill introduced by the Scottish Government, paragraph 3.4 of the Scottish Ministerial Code requires that the statement under section 31(1) must have been cleared with the Law Officers.

10. A Scottish Independence Referendum Bill has been drafted by the Scottish Government. The present reference arises because the Lord Advocate considers that she would be unlikely to have the necessary degree of confidence that the Bill does not relate to a reserved matter to clear a Ministerial statement under section 31(1) that the Bill is within the legislative competence of the Scottish Parliament. Given the importance of the issue to the Scottish Government, the Lord Advocate was requested by the First Minister to consider referring the question whether the Bill would be within the legislative competence of the Scottish Parliament to this court for decision. The Lord Advocate agreed to make such a reference.

11. The reference has been made under paragraph 34 of Schedule 6 to the Scotland Act, which provides:

2. The question referred

12. The question referred is:

3. Is the question referred a devolution issue?

13. Only a “devolution issue” can be referred to this court under paragraph 34 of Schedule 6. The expression “devolution issue” is defined by paragraph 1 of Schedule 6. So far as material, paragraph 1 provides:

1. (a) a question whether an Act of the Scottish Parliament or any provision of an Act of the Scottish Parliament is within the legislative competence of the Parliament,

2. (b) a question whether any function (being a function which any person has purported, or is proposing, to exercise) is a function of the Scottish Ministers, the First Minister or the Lord Advocate,

3. (c) a question whether the purported or proposed exercise of a function by a member of the Scottish Government is, or would be, within devolved competence,

4. (d) a question whether a purported or proposed exercise of a function by a member of the Scottish Government is, or would be, incompatible with any of the Convention rights or in breach of the restriction in section 57(4),

5. (e) a question whether a failure to act by a member of the Scottish Government is incompatible with any of the Convention rights,

6. (f) 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.”

14. The Lord Advocate relies on the final words of paragraph 1(f):

She maintains that the question which she has referred falls within that description. The Advocate General maintains that it does not. His arguments in support of that position can be considered under four headings.

(1) The Advocate General's first argument: “arising by virtue of this Act”, or by virtue of the Scottish Ministerial Code?

15. The first argument advanced by counsel for the Advocate General responds to the Lord Advocate's submission that the question she has referred is one “arising by virtue of this Act”, as required by paragraph 1(f), because it arises in the course of her performance of her function under the Scottish Ministerial Code of advising the Scottish Government, and in particular the minister in charge of the Bill, on whether the statement required by section 31(1) of the Scotland Act can be made. In response, counsel for the Advocate General point out that the Scotland Act contains no provision requiring the Lord Advocate to advise ministers in relation to statements made under section 31(1). Since the Lord Advocate's function in relation to such statements is not prescribed by the Scotland Act, a question arising in the course of performing that function is not, they submit, one “arising by virtue of this Act”. A requirement imposed by the Scottish Ministerial Code has no bearing on paragraph 1(f), since neither the existence nor the terms of the Code is prescribed by the Scotland Act.

16. These points are fairly made in response to the way in which the Lord Advocate initially put her case, but they are not fatal to her position as it developed, in response to questions from the bench, during the course of the hearing. As she came to accept, her role under the Scottish Ministerial Code does not bear on the present issue. Whether a question is one “arising by virtue of this Act” does not depend on whether the Lord Advocate is required by the Scotland Act to answer it. The question whether the provisions of a Bill would be within the legislative competence of the Scottish Parliament is one “arising by virtue of this Act” (subject to the other arguments advanced on behalf of the Advocate General), since it is a question which arises under section 31(1) for the person wishing to introduce the Bill, whether that be a minister or a private member. Provided the question is about reserved matters, as required by paragraph 1(f) of Schedule 6, the Lord Advocate is entitled to refer it to this court under paragraph 34 (subject, again, to the other arguments advanced on behalf of the Advocate General).

(2) The Advocate General's second argument: the scheme of legislative scrutiny established by sections 31 and 33 would be undermined

17. Sections 31 and 33 of the Scotland Act set out a number of provisions concerned with the scrutiny of Bills in order to assess whether they are within the legislative competence of the Scottish Parliament.

18. Section 31, headed “Scrutiny of Bills for legislative competence and protected subject-matter”, imposes obligations upon the person who wishes to introduce a Bill and upon the Presiding Officer of the Scottish Parliament. As has been explained, section 31(1) requires that the person in charge of a Bill must make a statement, on or before the introduction of the Bill in the Scottish Parliament, that in his or her view the provisions of the Bill would be within the legislative competence of the Scottish Parliament. In addition, section 31(2) requires that the Presiding Officer must decide, on or before the introduction of a Bill in the Scottish Parliament, whether or not in his or her view the provisions of the Bill would be within the legislative competence of the Scottish Parliament, and state his or her decision.

19. Section 33, headed “Scrutiny of Bills by the Supreme Court (legislative competence)”, confers upon certain Law Officers the power to refer certain questions of legislative competence to this court. In particular, section 33(1) provides:

The generality of that provision is, however, cut down by section 33(2), which provides:

1. (a) the period of four weeks beginning with the passing of the Bill, and

2. (b) any period of four weeks beginning with any approval of the Bill in accordance with standing orders made by virtue of section 36(5).”

Subsection (3) is immaterial to the present proceedings. Subsection 2(b) addresses the situation where a Bill has been approved by the Scottish Parliament following its reconsideration after this court's decision on a reference under section 33(1).

20. Counsel for the Advocate General argue that it would be surprising if the United Kingdom Parliament had set up a scheme for the reference of Bills under section 33, but had simultaneously enabled the Law Officers to make references of Bills or proposed Bills outside that scheme. The view that section 33 provides the only method of scrutinising a measure for legislative competence prior to Royal Assent is, they submit, supported by a number of considerations, including the following:

The definition of devolution issues in paragraph 1 of Schedule 6 refers to Acts of the Scottish Parliament but contains no reference to Bills or proposed Bills.

The Notes on Clauses which accompanied the Scotland Bill when it was considered by the United Kingdom Parliament, and were published online and in hard copy, state, in relation to paragraph 34 of Schedule 6:

Counsel submit that the words which we have italicised indicate a lack of intention on the part of the United Kingdom Parliament that questions about Bills should be referable under paragraph 34.

21. These submissions raise a number of matters of importance, particularly as regards the relationship between references under paragraphs 1(f) and 34 of Schedule 6, on the one hand, and under section 33, on the other.

22. We accept that a reference cannot be made under paragraphs 1(f) and 34 after a Bill has been introduced in the Scottish Parliament. As we have explained, section 33(1) confers a power on Law Officers to refer a question of legislative competence in relation to a Bill to this court, but section 33(2) then confines that power to a specified period after the passing of the Bill or its approval following an earlier reference. The clear implication is that it is only during those specified periods that a reference to this court can be made in respect of a Bill once it has been introduced. As was pointed out in Keatings v Advocate General for Scotland [2021] CSIH 25; 2021 SC 329, para 61, the time limits imposed on references by Law Officers under section 33(2) would be rendered nugatory if they could make a reference under another provision of the Scotland Act during the Bill's passage through the Scottish Parliament.

23. However, it does not follow that a reference cannot be made under paragraphs 1(f) and 34 of Schedule 6 before a Bill is introduced. As counsel for the Advocate General accepted, section 33 is not inconsistent with the existence of a power to refer a question relating to proposed legislation under paragraphs 1(f) and 34 prior to the introduction of a Bill.

24. We also accept that a bifurcation of issues relating to legislative competence is liable to arise if questions about reserved matters can be referred under paragraphs 1(f) and 34 of Schedule 6, since other issues affecting legislative competence cannot be so referred. The consequent possibility of consecutive references raising different issues in relation to the same Bill – first, a reference of questions about reserved matters under paragraphs 1(f) and 34 prior to the introduction of the Bill, and secondly a reference of other aspects of legislative competence under section 33 after the Bill has been passed – is a relevant consideration in construing Schedule 6. However, it is not necessarily a sufficient reason for cutting down the amplitude of the language used in paragraph 1(f) (“any other question arising by virtue of this Act about reserved matters”), particularly since the issue might be addressed through the exercise of the court's discretion to decline to accept a reference under paragraph 34. The same can be said of the argument that a reference under paragraphs 1(f) and 34 might conceivably be followed by a further reference under section 33 in the event that a Bill were to be amended during its passage through the Scottish Parliament so that it raised a further question as to whether it related to a reserved matter.

25. The other arguments advanced by counsel for the Advocate General are less cogent. First, the fact that paragraph 1 of Schedule 6 contains no reference to Bills is not necessarily significant, given that the terms of paragraph 1(f) are wide enough to include questions relating to proposed Bills.

26. Secondly, the statement in the Notes on Clauses does not advance the argument. The statement that paragraph 34 enables the Law Officers to refer “any vires question” could hardly be wider, and would cover the present eference. The following words, “even although it is not the subject of a judicial dispute and has not arisen in proceedings on a Bill”, do not cut down the width of that statement. We do not, however, attach particular weight to the Notes on Clauses. The document was drafted by Government officials and has no endorsement by the United Kingdom Parliament. It is much less significant than the language carefully chosen by the Parliamentary drafter and enacted by Parliament. Furthermore, paragraph 1(f) of Schedule 6 did not form part of the Bill at the time when the Notes on Clauses were produced, and the document does not therefore refer to it.

27. Thirdly, we see nothing anomalous about the possibility that United Kingdom Law Officers, as well as the Lord Advocate, might refer a question about reserved matters relating to a legislative proposal, if such a reference can be made under paragraphs 1(f) and 34. Similarly, we accept as the Lord Advocate did, that if her construction of the scope of paragraph 1(f) is right, then it must apply equally to the power in paragraph 4 of Schedule 6 to institute proceedings for the determination of a devolution issue in the Scottish courts. Again, we see nothing anomalous in the Law Officers having a parallel power to choose the appropriate forum for the determination of a particular issue. Neither of these powers creates a risk of frivolous or disruptive litigation given that the Law Officers can be expected to exercise the power only in appropriate circumstances.

(3) The Advocate General's third argument: an alternative construction of paragraph 1(f)

28. The Advocate General's third argument focuses on the fact that paragraph 1(f) includes any “other” questions about devolved competence, “other” questions in or as regards Scotland and “other” questions about reserved matters and asks the question “other than what?” The argument relates each component within paragraph 1(f) to the preceding paragraphs 1(a) to (e). Paragraphs 1(a) to (e) bring within the term “devolution issue” questions arising about devolved competence, in or as regards Scotland and reserved matters in particular contexts within the Scotland Act. So, the Advocate General argues, one must identify what else in that Act might need to be included by paragraph 1(f) as a devolution issue “other” than questions already covered by the first five sub-paragraphs.

29. In order to understand the Advocate General's third argument, it is helpful to break down paragraph 1(f) into its component parts, using notional sub-sub- paragraphs, as follows:

Following that notional annotation, this reference is concerned with the interpretation of paragraph 1(f)(ii).

30. Looking first at paragraph 1(f)(i)(A), Counsel for the Advocate General seek to identify the questions about whether a function is exercisable within devolved competence which might need to be covered by paragraph 1(f)(i)(A) because they are not already covered by paragraph 1(a)-(e), and in particular by paragraph 1(c), which already covers questions about whether the exercise of a function by a member of the Scottish Government would be within devolved competence.

31. Counsel for the Advocate General submit that there are a number of provisions of the Scotland Act (sections 92(4)(c), 104(2)(c) and 106(2)(b)) which employ the phrase “within devolved competence” in defining the powers of bodies other than the Scottish Government. The exercise of powers under those provisions does not fall within the ambit of paragraph 1(c) of Schedule 6, because paragraph 1(c) brings within the definition of “devolution issue” only questions whether the purported or proposed exercise of functions by members of the Scottish Government is or would be within devolved competence.

32. Against that background, counsel submit that paragraph 1(f)(i)(A) is concerned with questions arising under the provisions listed in para 31 above, ie questions about whether a function is exercisable within devolved competence by persons other than members of the Scottish Government. Although the language of paragraph 1(f)(i)(A), if considered in isolation, is also capable of covering questions concerning the exercise of functions within devolved competence by members of the Scottish Government, such questions are likely to fall within paragraph 1(c), and therefore to be excluded from the scope of paragraph 1(f)(i)(A) by the word “other”, in the phrase “any other question”. Given that the inclusion of the word “other” in paragraph 1(f)(i)(A) is intended to restrict that provision to functions which are not already included in paragraph 1(c), that provision must be given a more focused meaning, restricted to those provisions of the Scotland Act where it is needed.

33. Counsel next follow the same process of reasoning in relation to paragraph 1(f)(i)(B). The phrase “in or as regards Scotland” is used, in the context of a definition of limited powers, in a number of provisions in the Scotland Act, besides its use in defining legislative competence in section 29(2)(a), and hence its use, through its incorporation by section 54, in defining devolved competence. In particular, they submit, it is used in relation to functions other than those of members of the Scottish Government in sections 56(4)(a), 63(1), 88(6), 90(1) and 106(2)(a), and in paragraph L2 of Schedule 5. Against that background, they submit that paragraph 1(f)(i)(B) is concerned with questions arising under those provisions, because it is only those questions which are “other” than questions already within the definition under paragraph 1(c). Although paragraph 1(f)(i)(B) is also capable of covering questions concerning the exercise of functions in or as regards Scotland by the Scottish Ministers, such questions are likely to fall within paragraph 1(c), and therefore to be excluded from the scope of paragraph 1(f)(i)(B) by the word “other”.

34. Counsel next follow the same process of reasoning in relation to paragraph 1(f)(ii). The phrase “reserved matters” is used, in the context of a definition of limited powers, in a number of provisions of the Scotland Act, besides its use in defining legislative competence in section 29(2)(b), and hence its use, through its incorporation by section 54, in defining devolved competence. In particular, they submit, it is used in relation to non-legislative powers of the Scottish Parliament in sections 23(5) and (6), and in relation to United Kingdom ministers and cross-border public authorities in sections 56(4)(a), 58(4)(b), 88(2)(b) and (6), and 91(3)(d). Against that background, they submit that paragraph 1(f)(ii) is concerned only with questions arising under those provisions, and not with questions relating to the legislative competence of the Scottish Parliament, which are intended to arise only under section 33, after a Bill has been passed, or under paragraph 1(a) of Schedule 6, after legislation has been enacted.

35. Counsel submit that that interpretation of paragraph 1(f) is supported by the Explanatory Notes on the Scotland Act, which state in relation to that sub-paragraph:

Counsel point out that all of the examples given, apart from the last, fall under paragraph 1(f)(i), and concern the functions of bodies other than the Scottish Government.

36. Since, on counsel's analysis, paragraph 1(f)(ii) is not concerned with the legislative competence of the Scottish Parliament, they submit that it follows that the question referred by the Lord Advocate falls outside the scope of that provision.

37. We are not persuaded by this submission. The terms of paragraph 1(f) are very wide: “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” (emphasis added). When paragraph 1(f) is seen in its context, following paragraph 1(a) to (e), it has the appearance of a sweeping-up provision, designed to supplement the more precise provisions which precede it, so as to ensure that no gap is left. So understood, it ensures that it is possible for every conceivable question about whether a function is exercisable within devolved competence or in or as regards Scotland, and every conceivable question about reserved matters, to be decided by the courts. In particular, the words “any other question” would naturally be interpreted as meaning “any question, other than one falling within paragraph 1(a) to (e)”, and therefore as covering any question about reserved matters which is not covered by those provisions. It is understandable that the United Kingdom Parliament should have provided a means of ensuring that every such question is justiciable, since there could otherwise be situations where a limit on the exercise of a function could not be authoritatively determined.

38. That reading of paragraph 1(f), in accordance with the ordinary meaning of the words used, is consistent with the courts' general approach to the interpretation of the Scotland Act, as explained, for example, by Lord Hope (with whom the other members of the court agreed) in Imperial Tobacco Ltd v Lord Advocate [2012] UKSC 61; 2013 SC (UKSC) 153 (“Imperial Tobacco”), para 14:

We also note that Lord Hope said at para 33 of the same case that it would be wrong to pay any regard to the Explanatory Notes on the Scotland Act, which were produced by officials several years after the legislation had been enacted, and therefore did not form any part of the contextual scene of the statute.

39. Construing paragraph 1(f) according to the ordinary meaning of the words used is also consistent with the important function which paragraph 1 plays in the overall scheme of the Scotland Act. It is by no means limited to defining the scope of references to this court. Devolution issues can arise in any civil or criminal proceedings in any court or tribunal in Scotland (Part II of Schedule 6), England and Wales (Part III) or Northern Ireland (Part IV), as well as being the subject of a reference by a Law Officer to this court (Part V). The definition of a devolution issue in paragraph 1 is the key to the raising before any court or tribunal, anywhere in the United Kingdom, of any question arising under the Scotland Act, other than (since 2013) a question in relation to a compatibility issue as defined by section 288ZA of the Criminal Procedure (Scotland) Act 1995, as amended (which concerns certain questions arising in criminal proceedings in relation to Convention rights, ie rights and freedoms guaranteed by the European Convention on Human Rights, and retained EU law).

40. All of these considerations point towards treating the provisions mentioned in para 34 above as examples of provisions under which questions can arise about reserved matters, but not as being the only possible examples. In particular, reserved matters also feature in the definition of the legislative competence of the Scottish Parliament; and questions about that aspect of legislative competence may arise which do not concern enacted legislation or Bills which have been introduced in the Scottish Parliament, and do not therefore fall within the ambit of paragraph 1(a) or of section 33. The Lord Advocate maintains that the present case concerns a question of that kind.

41. In response, counsel for the Advocate General again raise the bifurcation point, and ask why, if questions of that kind about reserved matters were intended to fall within paragraph 1(f), that provision does not also extend to all the other aspects of legislative competence. There is undeniable force in this objection, and possible explanations of why the draftsman might have singled out reserved matters would be speculative. Nevertheless, a lack of tidiness in legislation is not unknown, and the fact that a particular interpretation would have an untidy outcome is not a fatal objection if that construction is nevertheless the most persuasive.

42. In short, (1) the breadth of the language used by the United Kingdom Parliament in paragraph 1(f), (2) the courts’ general approach to the construction of the Scotland Act, (3) the apparent purpose that the provision should sweep up any questions arising under the Act about reserved matters which are not covered by paragraphs 1(a) to (e), and (4) the critical role of paragraph 1(f) in relation to justiciability, all incline us to construe paragraph 1(f) in accordance with the ordinary meaning of the words used, rather than as being concerned only with the non- legislative powers of the Scottish Parliament and with the functions of United Kingdom ministers and cross-border public authorities.

(4) The Advocate General's fourth argument: why should there be a power to refer questions which the Lord Advocate is able to answer?

43. Counsel for the Advocate General submit that if the Scottish Government requires ministers to be guided by legal advice from the Law Officers when deciding whether they can make the statement required by section 31(1), and if, as in the present case, the Lord Advocate is not satisfied that a Bill would be within legislative competence, then the result is that the Bill cannot be introduced. It is, they submit, hard to see why this should be a matter of legal concern. The United Kingdom Parliament, they submit, would not have intended the resources of the court to be taken up with references by the Lord Advocate of provisions which she herself cannot confirm to be within legislative competence.

44. We are not persuaded by this argument. Law Officers perform an important role in providing legal advice to government, but they are not infallible. Further, as pointed out at paras 9 and 15-16 above, the person who has to form and state the opinion referred to in section 31(1) is the person in charge of a Bill, who may be either a minister or a private member. They too are not infallible when considering an issue of law regarding legislative competence. Moreover, the Law Officers, a minister or a private member (as the case may be) may believe that there is a reasonably arguable case that a Bill is within legislative competence, while not being sufficiently confident to be able to state positively that it is, being mindful that this is ultimately a question of law which only a court can resolve. However, following the practice set out in the Scottish Ministerial Code, a Scottish Government Bill cannot be introduced, however important it may be politically, unless the Lord Advocate is satisfied that its provisions would be within the legislative competence of the Scottish Parliament. If the Lord Advocate is not so satisfied, the Bill will not be introduced, and no reference can be made under section 33. But the Lord Advocate may be mistaken, with the consequence that a legitimate and politically important proposal for legislation will never see the light of day. The same position may arise in relation to a Bill introduced by a private member. Accordingly, it would be impossible to establish that a Bill which might in fact be within legislative competence (and as to which a Law Officer or its introducer thought there was a reasonable argument that it was within competence) was a proper and legitimate Bill fit to be passed by the Scottish Parliament.

45. It would be more consistent with the rule of law and with the intention of the Scotland Act that the Scottish Parliament should be able to exercise its powers where it has legislative competence for the Lord Advocate (if necessary, in the case of a private member's Bill, by acting at the request of that member) to be able to obtain an authoritative judicial decision on the point. Admittedly, only a decision on the scope of reserved matters can be obtained under paragraphs 1(f) and 34 of Schedule 6. Other aspects of legislative competence cannot be referred under those provisions. However, if legislation were construed so as to exclude anything short of a perfect solution, the best would indeed be the enemy of the good.

46. In confining the power to make a reference to Law Officers, the United Kingdom Parliament could also be confident that such references would be made responsibly in the public interest. That confidence is borne out by the fact that this is the first occasion on which a reference has been made by the Lord Advocate since the Scotland Act came into force 23 years ago. It is also the first occasion on which any Law Officer has referred a question in respect of a proposed Bill under any of the devolution statutes. Any risk that the court's resources might be unduly absorbed by such references is also mitigated by its discretion to decline to accept them.

47. For these reasons, we conclude that the question referred is a devolution issue, and that this court accordingly has jurisdiction to decide it.

4. Should the court decline to accept the reference?

48. On two occasions in the past, this court has declined to decide questions referred to it by the Attorney General for Northern Ireland under paragraph 34 of Schedule 10 to the Northern Ireland Act 1998, which is the provision corresponding to paragraph 34 of Schedule 6 to the Scotland Act, on the basis that it possesses an inherent discretion to do so. Counsel for the Advocate General submit that the court should exercise its discretion to decline to decide the question which is the subject of the present reference.

49. The two references from Northern Ireland were very different from the present case. In the first of those cases, Reference by the Attorney General for Northern Ireland of devolution issues to the Supreme Court pursuant to Paragraph 34 of Schedule 10 to the Northern Ireland Act 1998 [2019] UKSC 1; [2020] NI 793, the court adjourned the reference in circumstances where inter partes proceedings were pending which would allow most if not all of the issues to be raised, and in which the Attorney General had the power to intervene and make a reference. Lord Kerr, giving the judgment of the court, explained that it was generally desirable that legal questions should be determined against the background of a clear factual matrix rather than as theoretical issues of law.

50. In the second case, Reference by the Attorney General for Northern Ireland of devolution issues to the Supreme Court pursuant to Paragraph 34 of Schedule 10 to the Northern Ireland Act 1998 [2020] UKSC 2; [2020] NI 820, the Attorney General sought to challenge the compatibility of United Kingdom legislation with Convention rights, by referring a question concerning the issuing by the devolved administration of lists of postcodes which were incorporated by reference into the commencement order made by the United Kingdom Government. The United Kingdom legislation was the subject of a direct challenge in other proceedings in England and Wales. The court refused to accept the reference on two grounds. First, it was said, the court must retain a discretion whether to deal with a reference on a devolution issue where that issue is to be raised in proceedings where the claimed incompatibility of the measure with Convention rights occupies centre stage, as opposed to its appearance via a side wind. Secondly, it was said, although the production of the postcode lists was an act of a devolved institution, the relative isolation of that act from the introduction of the United Kingdom legislation threw into stark relief the inappropriateness of regarding the preparation of the lists as an act sufficient to give rise to a devolution issue.

51. Neither of the Northern Ireland cases arose in the same circumstances as the present case, but counsel for the Advocate General submit that they demonstrate that the court can decline to accept a reference where it is not an appropriate vehicle for the determination of the issue in question. They argue that that is also the position in the present case, particularly for the following reasons:

Any Bill introduced into the Scottish Parliament may not be in the same terms as the proposed Bill presently before the court, with the consequence that the court's decision in respect of the proposed Bill may not be determinative. A further reference would then be necessary under section 33.

Any Bill introduced into the Scottish Parliament may be amended during its passage, with the same consequence.

The present reference cannot deal with issues of legislative competence which fall outside the scope of paragraph 1(f), such as whether a Bill providing for a referendum on Scottish independence would be incompatible with section 28(7) of the Scotland Act, which protects the power of the United Kingdom Parliament to make laws for Scotland.

A practical problem in assessing whether the provisions of a proposed Bill would relate to reserved matters arises from the absence of the policy memorandum and other documents which would accompany a Government Bill on its introduction into the Scottish Parliament. Such documents can be taken into account in identifying the purpose and effect of legislation, as required by section 29(3) of the Scotland Act (set out at para 57 below): Martin v Most [2010] UKSC 10; 2010 SC (UKSC) 40, para 25.

It is inappropriate, they submit, for the Lord Advocate to treat this court as a legal advice centre. It is a normal aspect of the responsibilities of a Law Officer to provide legal advice to government on her own responsibility. The substantive question in the present case is, they submit, not even one of particular difficulty.

52. In support of that submission, counsel cite Yalland v Secretary of State for Exiting the European Union [2017] EWHC 630 (Admin). That case concerned challenges by a number of individuals to a decision by the United Kingdom Government to leave the European Economic Area. The proceedings were brought before any such decision had been made. The Divisional Court refused permission to apply for judicial review. It observed at para 25:

Observations to similar effect were made in the cases of R (Counsel General for Wales) v Secretary of State for Business, Energy and Industrial Strategy [2021] EWHC 950 (Admin); [2022] EWCA Civ 118 and Keatings v Advocate General for Scotland, where proceedings concerning the legislative competence of the Senedd and the Scottish Parliament respectively, raised in advance of the introduction of legislation, were held to be premature. The approach followed in these authorities is eminently sensible. As Lord Phillips of Worth Matravers MR observed in an earlier case, the court should not be used as a general advice centre. The danger is that it will enunciate propositions of principle without full appreciation of the implications that these will have in practice: R (Burke) v General Medical Council [2005] EWCA Civ 1003; [2006] QB 273, para 21.

53. However, these authorities were all concerned with ordinary litigation. There may be greater scope for this court to entertain issues that might not otherwise be ripe for decision in the context of references under its devolution jurisdiction. Nevertheless, we accept that counsel for the Advocate General makes some powerful points, which may often be compelling. We do not, however, find them compelling in the circumstances of the present case. As the Lord Advocate submitted, those circumstances are exceptional, for the following reasons:

(1) The reference has been made in order to obtain an authoritative ruling on a question of law which has already arisen as a matter of practical importance. 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.

(2) The question relates to a proposed Bill which, the court is informed by the Lord Advocate, the Scottish Government intends to introduce in the event that the court decides that it does not relate to reserved matters. All the provisions of the Bill which are material to the question referred will, the court is informed, be introduced in the same form as they are in before the court.

(3) The purpose and effect of the material provisions of the Bill are apparent without the assistance of a policy memorandum or related papers.

(4) Given the brevity and clarity of the provision in issue in this case, and the Scottish Government's commitment and practical ability to secure its enactment in its present form, the court does not have to be concerned in this case about the possibility that the Bill might be materially amended during its passage through the Scottish Parliament.

(5) In the circumstances of this case, the court can discount the risk that a further reference under section 33 is likely to be needed in order to deal with materially different aspects of legislative competence.

(6) As we have indicated at paras 44-45 above, we do not consider that the Lord Advocate, in making the reference, is acting other than with a proper sense of her responsibilities. The question referred is not of a routine character. It is understandable that the Lord Advocate should have decided that it should be referred to this court in the public interest.

54. For these reasons, we conclude that the court should accept the reference.

5. Consideration of the question referred

55. In order to decide the question referred, the court will begin by considering the arguments presented by the Lord Advocate, and the response to those arguments by counsel for the Advocate General. We will then consider the arguments presented by the Scottish National Party, and the Advocate General's response.

(1) The arguments of the Lord Advocate and the Advocate General