In his foreword, Lord Smith writes:
The Scottish Parliament will be made permanent in UK legislation and given powers over how it is elected and run. The Scottish Government will similarly be made permanent.
In the report itself, these ideas are fleshed out (slightly) in the following terms:
UK legislation will state that the Scottish Parliament and Scottish Government are permanent institutions.
The report goes on to say that:
The Sewel Convention will be put on a statutory footing.
Viewed from a purist legal-constitutional perspective, these statements promise more than they can deliver — but, this post will argue, this does not necessarily diminish their significance.
Can the UK Parliament relinquish its authority?
Saying (as the report does) that UK legislation “will state” that the Scottish Parliament and Government are permanent institutions is not the same as saying (as the foreword does) that the Scottish Parliament “will be made” permanent. An Act of the UK Parliament might say that the Scottish Parliament is permanent, but that will not necessarily make it so. This follows because, at least on an orthodox analysis, the UK Parliament is incapable of legally diminishing its sovereign authority.
The point was well made by Laws LJ in Thoburn v Sunderland City Council  EWHC 195 (Admin),  QB 151. The focus in that case was upon the relationship between EU and UK law, which raised questions about whether the European Communities Act 1972 (“ECA”) was in any sense entrenched, so as to make it capable of prevailing over other, including subsequent, legislation. Laws LJ thought not:
Whatever may be the position elsewhere, the law of England disallows any such assumption. Parliament cannot bind its successors by stipulating against repeal, wholly or partly, of the ECA. It cannot stipulate as to the manner and form of any subsequent legislation. It cannot stipulate against implied repeal any more than it can stipulate against express repeal. Thus there is nothing in the ECA which allows the Court of Justice [of the EU], or any other institutions of the EU, to touch or qualify the conditions of Parliament’s legislative supremacy in the United Kingdom. Not because the legislature chose not to allow it; because by our law it could not allow it. That being so, the legislative and judicial institutions of the EU cannot intrude upon those conditions. The British Parliament has not the authority to authorise any such thing. Being sovereign, it cannot abandon its sovereignty.
Laws LJ went on to suggest that the ECA was a “constitutional statute” and was for that reason immune from implied repeal, but that is a distinct matter (to be considered later). Questions about the status of the Scottish Parliament clearly arise in a context different from that which applied in Thoburn, but they raise comparable fundamental issues. If the UK Parliament were legislate to the effect that the Scottish Parliament “is permanent”, the implication would be that the UK Parliament had become incapable of abolishing the Scottish Parliament. Equally, if the Sewel Convention — which provides that the UK Parliament will not normally legislate on devolved matters absent the consent of the relevant devolved legislature — were “put on a statutory footing”, the implication would be that the UK Parliament was legally disabled from legislating on devolved matters absent such consent.
However, orthodox constitution theory — as the dictum above from Thoburn indicates — suggests that any statements along these lines that were inserted into a UK statute would not be legally binding. Because, “[b]eing sovereign, it cannot abandon its sovereignty”, any provision in legislation purporting to limit the UK Parliament’s capacity to legislate would be ineffective: it would constitute an attempt to do the one thing that a sovereign legislature cannot do.
Viewed, then, through a purist legal-constitutional lens, the promises concerning a “permanent” Scottish Parliament ring rather hollow. However, three alternative perrspectives yield rather different conclusions. The remainder of this post will attempt to do no more than briefly sketch those three alternatives in increasing order of potential legal significance.
The first possibility is that UK legislation providing for a permanent Scottish Parliament and placing the Sewel Convention on a statutory footing would be politically but not legally significant. In other words, they would constitute a crystal-clear commitment on the part of the Westminster Parliament to desist from interfering in Scottish devolved affairs. Importantly, however, on an orthodox legal analysis, this commitment would amount to an undertaking not to exercise sovereign authority that would persist in Westminster, as distinct from something that would detract from that sovereign authority. An analogy may be drawn with section 4 of the Statute of Westminster 1931, which provides that:
No Act of Parliament of the United Kingdom passed after the commencement of this Act shall extend, or be deemed to extend, to a Dominion as part of the law of that Dominion, unless it is expressly declared in that Act that that Dominion has requested, and consented to, the enactment thereof.
The effect of this provision was not to legally disable the UK Parliament, as a matter of UK constitutional law, from legislating for Dominions against their wishes — but, as Lord Denning MR observed in Blackburn v Attorney-General  1 WLR 1037, ‘Freedom once given cannot be taken away. Legal theory must give way to practical politics.’ A similar point might be made in relation to devolution, its technical legal reversibility being eclipsed by the political difficulty — if not impossibility — of putting the devolution genie back in the bottle.
Second, it may be possible for a provision in a UK statute that sought to secure the permanence of the Scottish Parliament to be entrenched contingently rather than absolutely. In other words, rather than attempting absolutely to prevent future UK Parliaments from acting inconsistently with such a provision (by abolishing the Scottish Parliament), an attempt might instead be made to stipulate conditions that would have to be fulfilled before the permanence provision could be overridden. For instance, a requirement of a special (e.g. two-thirds rather than simple) majority or a special form of words (e.g. express rather than implied) might be required. However, the possibility of such contingent — or “manner and form” — entrenchment is not firmly established as a matter of UK constitutional law. Some cases — including Thoburn v Sunderland City Council  EWHC 195 (Admin),  QB 151 and Ellen Street Estates v Minister of Health  1 KB 590 — pour cold water on the idea. Other decisions, however, are more sympathetic, certain of the Law Lords’ speeches in Jackson v Attorney-General  UKHL 56,  1 AC 262 being cases in point.
If contingent entrenchment were deemed possible, then interesting questions would arise concerning how far this idea might be pressed. Could, for instance, the Westminster Parliament contingently entrench a provision guaranteeing the permanence of the Scottish Parliament on the basis that such a provision could not be overridden or repealed unless a condition requiring the Scottish Parliament’s consent were fulfilled? This would technically amount to contingent entrenchment — it would be a condition capable of being fulfilled, thereby leaving open the theoretical possibility of abolition — but it would amount to a condition so hard to fulfil and so unlikely to be fulfilled as to disclose an effective diminution in Westminster’s authority. This, in turn, raises questions about whether any theory of contingent entrenchment would admit of conditions outwith the control of the Westminster Parliament (compare, e.g., special-majority requirements and requirements concerning referendums or the approval of an external institution).
Constitutional statutes and common-law constitutional values
A third possibility is that the courts might regard a provision stipulating that the Scottish Parliament was sovereign to be a “constitutional” provision. (The courts might instead regard the whole of the UK Act concerned to be a constitutional statute, although, as David Feldman, “The nature and significance of ‘constitutional’ legislation” (2013) 129 LQR 343 shows, the notion of constitution provisions as distinct from statutes makes more sense.) Applying the kind of approach advocated in Thoburn and in R (HS2 Action Alliance) v Secretary of State for Transport  UKSC 3,  1 WLR 324, this would suggest that the provision in question would enjoy a superior legal status to ordinary statutory provisions. However, at least in its current state of development, the notion of constitutional legislation (or provisions) appears to suppose that any such special status amounts in practice to nothing more radical than immunity from implied repeal. This hardly suggests that characterising the permanence provision as a constitutional one would confer significant legal (as distinct from political) security upon the Scottish Parliament.
However, one of the significant aspects of the analysis in HS2 (about which I have written at greater length here) is that attention was paid to the relationship between constitutional values and statutory constitutional provisions. In HS2, the constitutional fundamentality that was ascribed to Article 9 of the Bill of Rights 1689 was said to derive not from the fact that the Bill of Rights was a constitutional statute, but from the normative significance of the value codified by Article 9. The Supreme Court therefore doubted whether the ECA 1972, notwithstanding that it has been characterized as a constitutional statute, would prevail (absent express provision) over the value codified by Article 9.
Viewed from this perspective, a provision in a UK statute stipulating the Scottish Parliament’s permanence might equally be considered to be a codification of the underlying constitutional value of the autonomy and enduring nature of devolved institutions. Significantly, HS2 contemplates the possibility that not all constitutional values and provisions might be equal, and that some might be deemed to enjoy a deeper level of fundamentality than others. A statutory provision guaranteeing the permanence of the Scottish Parliament might well fall into such a category — and, if it did, it might turn out that the practical consequences of its inclusion in such a category went beyond mere immunity from implied repeal. Whether any constitutional value is so fundamental as to be wholly beyond disturbance by Westminster is, of course, an unresolved matter — but the possibility of such a super-fundamental category of values is of a piece with oft-cited judicial assertions in Jackson to the effect that rule-of-law requirements such as the availability of judicial review may point towards in extremis limitations upon the UK Parliament’s authority.
It is of the essence of our unwritten constitution that we cannot predict with certainty how constitutional crises that test the limits of legislative authority will play out. However, it is fair to say that our courts are sketching a constitutional order that is increasingly normatively rich, and which forms an increasingly hostile environment for an unreconstructed notion of the sovereignty of the Westminster Parliament. It would be foolish to assert with certainty that if a future UK Parliament were to renege on the settlement proposed by the Smith Commission, it would — as a matter of law — be able straightforwardly to do so. It would, however, be equally foolish to assert that courts would stop in their tracks a UK Parliament that wished to proceed in such a way. Traditional analysis holds that the hard edges are knocked off the legal doctrine of parliamentary sovereignty by means of recourse to political constitutionalism. However, as I have argued elsewhere, the relationship between merely political and more fundamentally constitutional forms of restraint requires further exploration. There are, arguably, points at which the distinctions between legal, political and constitutional forms of restraint begin to break down — and the more fundamental the norm at stake, the greater is the stress under which such distinctions are placed.
Against this background, the proposal to legislate for restraints upon the UK Parliament — so as to attempt to secure the permanence of the Scottish Parliament — is intriguing. One way of understanding the proposal is as a tacit acknowledgment that reliance upon political restraint in Westminster is no longer perceived — from a Scottish perspective — as sufficient, and that the sort of harder, legal dividing lines familiar in federal systems are regarded as necessary. The difficulty is that grafting such an approach onto a system premised upon the sovereignty of a central legislature is far from straightforward. This problem, however, is one that stems from an understanding of the UK constitutional system that may be getting past its sell-by date.
Viewed in this way, the proposals of the Smith Commission harness what might, in time, turn out to have been the dawn of a new era of constitutionalism in the UK: one that is not content to rely purely upon political constitutionalism as a means by which to contain the potential for excess implied by legislative supremacy, but which instead invokes the constitution itself — in potentially legal as well as political guise — as a vehicle for supplying such restraint. It follows that while, from an orthodox legal-constitutional perspective, guarantees as to the Scottish Parliament’s permanence contained in a UK statute would not be worth the paper they were printed on, it should not be taken for granted that that perspective is the right one from which to attempt to gauge the political or legal implications of what is being proposed.