By Nicholas Kilford 

PhD Candidate, University of Cambridge

On 6 October 2021 the Supreme Court handed down its judgment in the UNCRC and ECLSG Reference cases. In a previous post published beforehand (available here) I set out what was at issue in the case and what might have been expected from the judgment. On the substantive issue, namely whether it was within the Scottish Parliament’s legal powers to enact certain parts of the Bills, the Court overwhelmingly said ‘no’. Across the two Bills, a total of six provisions were held to be outside the Scottish Parliament’s competence, five because they ‘modified’ Westminster’s power to make laws for Scotland, and one because it concerned an area of policy over which the Scottish Parliament is not able to legislate (a reserved matter). However, that post predicted that in reaching its conclusions the Court would address five questions. In this post I explore how the Court answered them, as well as how they dealt with one additional question. 

What is the Court’s view of key constitutional principles? 

There are three important constitutional principles that are at the fore of this judgment: parliamentary sovereignty, the rule of law and devolved autonomy. The first two of these are considered in more depth below, but they each shape the interpretation of the third. From the very beginning of the judgment, it is clear that the Supreme Court is adopting quite a narrow conception of devolution, interpreting its founding legislation far from favourably for the Scottish Parliament. Although in previous cases the courts have sometimes said devolution legislation should be ‘interpreted generously and purposively’, the Court here rejected that thinking, saying that it ‘must be interpreted in the same way as any other statute’. This ‘minimal’ conception of devolution is apparent in different parts of the judgment, with the restrictions in the Scotland Act 1998 (which defines the powers of the Scottish Parliament) sometimes being read broadly and the provisions which empower the Scottish Parliament being read narrowly. One of the examples of this ‘broad’ construction can be found in the Court’s answer to the second question below. 

What does it mean to ‘modify’ the Scotland Act? Can the Scottish Parliament impose conditions on the legal effect of Acts of the UK Parliament? 

Because the Scottish Parliament — or ‘Holyrood’ — has the power to amend and repeal Acts of the Westminster Parliament within its areas of competence, the Scotland Act allows Westminster to protect some of its legislation from this interference. Legislation that is protected in this way—‘protected enactments’—cannot be ‘modified’ by the Scottish Parliament. But what exactly does ‘modify’ mean in this context? The existence of reserved matters suggests that the Scottish Parliament can legislate in the same area as a protected enactment, so what level of tension between the Scottish legislation and the protected provisions is needed to amount to a ‘modification’?  On this issue the Court uncompromisingly adopted its own reasoning in a previous case, the Continuity Bill. In that case, the Court had provided a very broad test for modification, one that is easily met and was predictably satisfied in this case. Provisions which gave Scottish Courts wide interpretive powers, the power to strike down Westminster’s legislation, and even to subject it to political condemnation clearly, in the Court’s view, ‘modified’ Westminster’s power to make laws for Scotland. This represents quite a broad reading of ‘modification’ and so a narrow conception of devolution itself — something that might well have implications for the future. 

What is the relationship between ‘the power to make laws’ and parliamentary sovereignty itself? 

One of the decisive issues in the Continuity Bill case was a distinction the Court drew between Westminster’s ‘unqualified’ power to make laws (which the Scottish Parliament cannot lawfully modify) and parliamentary sovereignty. In this case, the Court leans very heavily on this distinction, suggesting that the power to make laws is a more fragile concept than sovereignty, one which is easily modified, and which essentially acts as a limitation on the Scottish Parliament’s powers. These Bills might not offend parliamentary sovereignty—that concept is sufficiently flexible that they could not offend it—but the power to make laws is far more sensitive to the Scottish Parliament’s legislation. In practice, this means that devolution is more limited than had previously been thought. It used to be understood that devolution was (necessarily) limited by the principle that the Westminster Parliament is sovereign. But it now turns out that devolution is also limited by the broader principle that the Scottish Parliament cannot do anything that would be inconsistent with Westminster’s ‘unqualified’ power to make laws for Scotland.  

The Scottish Parliament can repeal legislation: can it delegate a power to the courts to do the same? 

On this point, the Court said that ‘the fact that the Scottish Parliament has the power to repeal an Act of Parliament does not entail that it has the power to authorise the courts to declare that unrepealed Acts of Parliament have ceased to be law.’ Here, the Court’s suggestion is that there is an important difference between the Scottish Parliament itself deciding to repeal an Act of Parliament, and the Scottish courts being allowed to do the same. The Court said that Westminster, through the Scotland Act, permits only the Scottish Parliament to exercise this repealing power. It cannot delegate it to another body such as a court. These Bills, in allowing an external authority to dictate the legal validity of Acts of the Westminster Parliament, fell foul of the requirement set out in Continuity Bill case that ‘the Scottish Parliament cannot make the effect of Acts of Parliament conditional on decisions taken by other institutions’. As a consequence, the answer to this question is ‘no’. 

How far does the interpretive obligation stretch? 

If a piece of the Scottish Parliament’s legislation ‘could be read in such a way as to be outside competence’, the Scotland Act requires that it ‘is to be read as narrowly as is required for it to be within competence, if such a reading is possible’. In this way, Scottish legislation that might seem to be outside the Scottish Parliament’s power can be rescued from unlawfulness by being read in a sufficiently restricted way. However, in the Court’s view this ‘interpretive obligation’ is not capable of curing every competence issue within Scottish legislation. This is especially so when it is being intentionally relied by the Scottish Parliament to keep its legislation within competence. A significant element of the Court’s reasoning was that, if this interpretive obligation were to be relied on too heavily, then the legislation itself would no longer be an accurate representation of the law and would be unclear. The courts would have to interpret the law constantly in order for people to understand their rights, duties and obligations. The Court said that this could not have been what the Westminster Parliament intended when it included the interpretive obligation in the Scotland Act. 

An additional question: What is the impact of the Human Rights Act on parliamentary sovereignty? 

One issue that was explored more prominently in the judgment than many were expecting was the relationship between the Human Rights Act (HRA) and parliamentary sovereignty. Because the Bills in question bear a striking (and intentional) resemblance to the HRA, the Court considered it useful to discuss the HRA’s bearing on Parliament’s ‘power to make laws’. This was so that it could distinguish the HRA from the Bills in question. However, the judgment’s conclusions about the HRA make for some quite revelatory reading. 

On the Court’s analysis, the HRA has some striking implications for Parliament’s legislative freedom. The Court considers that one important provision of that Act (section 3, which requires courts, as far as possible, to read legislation compatibly with rights protected by the HRA) ‘plainly impose[s] a qualification upon its legislative power’ because it requires courts ‘to modify the meaning and effect of legislation enacted by Parliament’. The Court suggests that another provision of the Act (section 4, which allows courts to issue a declaration if legislation is incompatible with relevant rights) puts political pressure on Parliament and therefore actually qualifies parliamentary sovereignty itself (the Court temporarily jettisoning the distinction it had otherwise made use of between unqualified legislative power and sovereignty). Neither of these claims are uncontroversial. The HRA has for a long time been generally thought of as innocuous for sovereignty, but the Supreme Court here suggests otherwise. 

Perhaps even more revelatory is the reason the Court gives as to why the HRA is palatable but the same kinds of provisions in these Bills are not. This is so because the HRA, and other limitations on sovereignty (unlike these Bills), are imposed upon Westminster by itself. This reasoning is fascinating; the Court takes it for granted that Parliament can limit its own sovereignty in this way, yet this view is also far from uncontroversial. Furthermore, it remains to be seen whether this will have implications for both the HRA (given that it is now regarded as in tension with sovereignty) and the wider constitution, sovereignty now being understood as a broad, flexible and politically sensitive concept. 

For a more technical analysis of the case, see Mark Elliott and Nicholas Kilford, ‘Devolution in the Supreme Court: Legislative Supremacy, Parliament’s ‘Unqualified’ Power, and ‘Modifying’ the Scotland Act’, U.K. Const. L. Blog (15 October 2021)  

(available at 

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