In his judgment in Ismailov v Foreign Secretary, Saini J appears to endorse two incompatible views of the principle of legality. One of those views reconfigures a principle that has traditionally brought normatively independent common law constitutional principles into relationship with legislation, instead reducing it to a tool for determining the “true intention” of Parliament. This forms part of a wider trend in the courts’ constitutional case law that amounts to a form of jurisprudential revisionism which is in opposition to the history and practice of the common law – and which is to be deprecated.
Ismailov v Secretary of State for Foreign, Commonwealth and Development Affairs [2026] EWHC 1188 (Admin) involved a challenge to the imposition of devastating economic sanctions on the claimant. He was the biological nephew of an Uzbek-Russian billionaire with alleged close ties to Vladimir Putin, but there was no suggestion that the claimant himself was involved in any wrongdoing or other relevant misconduct. Rather, he was sanctioned due simply to his relationship with his uncle. That was possible only because the government, via secondary legislation, had extended the pre-existing sanctions regime to cover those who are an “immediate family member” – which explicitly includes “a niece or nephew” – of someone who, like the claimant’s uncle, is an “involved person”. The claimant sought statutory review under section 38 of the Sanctions and Anti-Money Laundering Act 2018, thereby requiring the court, under section 38(4), to “apply the principles applicable on an application for judicial review”.
In what follows, I address two aspects of the judgment, focussing respectively on its implications for constitutional doctrine and constitutional theory, and conclude by arguing that Ismailov forms part of a broader current of judicial thinking that amounts to a revisionist project which risks undermining the common law’s already modest capacity to uphold basic constitutional norms.
Constitutional doctrine
The claimant’s challenge was brought on seven grounds, all of which failed before Saini J in the Administrative Court. In refusing to conclude that it was disproportionate or irrational to sanction someone purely by virtue of familial happenstance and absent any evidence that the claimant was in a position to influence his uncle, Saini J relied on and followed the notably deferential judgment of the Supreme Court in Shvidler v Secretary of State for Foreign, Commonwealth and Development Affairs [2025] UKSC 30, about which I have written in another post. There is plenty that can, and no doubt will, be said about that aspect of Saini J’s judgment. But, to me at least, its most striking element concerns its treatment of a separate argument made by the claimant in relation to the principle of legality.
That principle was classically defined in the following terms by Lord Steyn in R v Secretary of State for the Home Department, ex parte Pierson [1998] AC 539:
Parliament does not legislate in a vacuum. Parliament legislates for a European liberal democracy founded on the principles and traditions of the common law. And the courts may approach legislation on this initial assumption. But this assumption only has prima facie force. It can be displaced by a clear and specific provision to the contrary.
In Ismailov, counsel for the claimant argued that extending the sanctions regime so as to render a person “liable to designation because by ‘pure accident of birth’ they happen to be an immediate family member of an ‘involved person’” contravened the principle of legality because it is “liable to produce arbitrary and capricious outcomes and was a violation of legal certainty principles”. It might have been added that by facilitating the imposition of draconian restrictions on family members, the extended sanctions regime sought to license extensive state interference with fundamental rights including property rights, whose recognition at common law has a long and deep history.
However, Saini J had no truck with the possibility that such rights were at stake, instead opining that: “The only rights capable of engaging the principle of legality in this sense in this case are Article 8 ECHR [the right to respect for private and family life] and [Article 1, Protocol 1] ECHR [the right to peaceful enjoyment of possessions].” This is puzzling for two reasons. First, the principle of legality does not operate upon ECHR rights, not least because it would be redundant given the existence of section 3 of the Human Rights Act 1988, which amounts, in respect of Convention rights, to a statutory equivalent to the principle of legality. Second, it is hard to fathom why Saini J concluded that only ECHR rights were potentially in play, given the long pedigree of pertinent common law rights, including, most obviously, the right to property.
At a purely doctrinal level, therefore, the treatment of the principle of legality in Ismailov leaves much to be desired – a point that is underlined when we consider the relevant statutory framework. Section 11(3) of the 2018 Act permits the making of regulations that determine that an “involved person” – upon whom sanctions can be imposed – can be a person who is “associated with” another “involved person”. This plainly allows the net to be cast wider than what might be termed primary involved persons (such as, in this case, the uncle). But the legislation does not stipulate how far Ministers can go when it comes to the casting of the net. Instead, section 11(6) merely says that regulations “may make provision, for the purposes of the regulations, as to the meaning of a person’s … being ‘associated with’ another person”.
Why should we conclude that, in saying this, Parliament authorised Ministers to make regulations so far-reaching as to permit the sanctioning of family members whose relationship with the primary involved person is no more than biological? There is no good reason why this vaguely worded power could not have been read, in accordance with the principle of legality, more narrowly than Saini J was prepared to read it, bearing in mind the far-reaching consequences for individuals who find themselves within the sanctions regime. Yet the only justification Saini J offered for his conclusion that the principle of legality could not assist the claimant consists of the following reasoning:
[E]ven if the public law principle of legality was engaged it is of no assistance given the clear and unambiguous terms of the statutory scheme. Parliament has squarely confronted the possibility that designation might be made solely on grounds of association, but has expressly required subordinate legislation to provide for designation on that basis, and permitted subordinate legislation to further specify the scope of such association.
But saying that Parliament has “squarely confronted the possibility that designation might be made solely on the grounds of association” does not get us very far, since Parliament says nothing about how wide the net can be cast. Nor does it get us any further to say that Parliament has provided for the extent of the net to be determined by subordinate legislation, given that Parliament, once again, has said nothing specifically about how far such legislation can go. Indeed, properly understood, the statutory scheme provides a classic example of circumstances in which the principle of legality can – and should – be used to interpret vague legislation in order to align it with fundamental principle. That such a possibility was dismissed out of hand is striking, to say the least. Why, then, did Saini J adopt such an approach?
Constitutional theory
The answer lies in paragraph 86 of his judgment, which is worth quoting in full – along with the heading that precedes it:
Public law legality: a narrow principle of construction and no more
The public law principle of legality does not provide an independent ground for challenging subordinate legislation as unlawful. In relation to the scope of this principle and prior to the hearing, I drew to the attention of the parties the text of a speech given by Lord Sales to High Court Judges on 18 November 2025 (linked here). In the speech, Lord Sales provides a helpful summary of the scope and application of the public law principle of legality. As he explains, the ultimate justification for the principle of legality is that it is a “tool” for determining and properly following the intention of Parliament. I also referred Counsel to the illuminating discussion of the principle of legality by Singh LJ at [35]-[52] in his Public Law lecture, given at the London School of Economics on 11 March 2026 on Substantive Principles of Administrative Law: Developments since 1987. As Singh LJ explains, it is a principle of statutory interpretation that general words in primary legislation will not be construed to confer power on the executive to infringe basic rights protected by the common law. So, the principle of legality in the public law sense is directed at seeking to ascertain the true intention of Parliament, as the basis for the interpretation of legislation. In short, it operates as a rule of construction under which general or ambiguous statutory language may be construed in a manner that preserves fundamental rights. The principle means not only that Parliament cannot itself override fundamental rights by general or ambiguous words, but also that it cannot confer on another body, by general or ambiguous words, the power to do so.
The first striking feature of this paragraph consists of its first sentence. Is Saini J right to say that the principle of legality “does not provide an independent ground for challenging subordinate legislation as unlawful”? It depends on what is meant by “independent”. Conceptually, the principle of legality – as Lord Steyn explained in the passage from Pierson that is quoted above – is an interpretive principle. As such, it might be technically correct to say that it is not an “independent ground” of review. However, in practice, once the principle of legality – or, indeed, any interpretive conclusion – is combined with the ultra vires concept, it undoubtedly does become a ground of challenge in its own right, since any use of the relevant statutory power in breach of the limits read into it via the principle of legality would result in ultra vires, and therefore unlawful, administrative action. The Law Reports are replete with cases in which the principle of legality, deployed thus, has resulted in successful challenges to executive action – including subordinate legislation.
The second striking feature of this part of the judgment concerns the two judicial lectures that are cited. Leaving to one side the oddity of basing his analysis of the principle of legality argument on such lectures – rather than on, say, the vast body of case law and academic literature that exists in this area – it is remarkable that Saini J invokes the two lectures without adverting to the fact that they present sharply contrasting accounts of the principle of legality. Singh LJ’s lecture, helpful though it might be, is unremarkable, providing as it does an account of the standard case law and advancing an orthodox definition of the principle of legality as a “principle of statutory interpretation that general words in primary legislation will not be construed to confer power on the executive to infringe basic rights protected by the common law”. That view of the principle of legality accords with the final two sentences of paragraph 86 of Saini J’s judgment and is consonant with the long-standing history and practice of the common law (which is addressed further in the final section of this post).
Lord Sales’s lecture – on which Saini J also places reliance, and to which I have responded in detail elsewhere – is a different kettle of fish. Advancing what amounts to a revisionist view – a characterisation that is justified below – of the principle of legality, Lord Sales argues that it can bite only upon a constitutional principle (or right) that is “so clear as to be taken to be recognised by Parliament itself, so that it is plausible to maintain that Parliament legislated on the unspoken assumption that the statute was to be taken to be modified by the principle — which is the basic theory underlying the principle of legality”. This echoes the view advanced by Lord Sales in an academic article (“Legislative Intention, Interpretation, and the Principle of Legality” (2019) 40 Statute Law Review 53) that “the principle of legality is properly to be viewed as an aspect of legislative intent” such that courts must ask whether the relevant constitutional norm “can plausibly be taken to have had such a level of acceptance among parliamentarians … as to form part of the legislative context in which they meant to act”. This thinking is reflected in Saini J’s description of the principle of legality as a principle that is “directed at seeking to ascertain the true intention of Parliament”.
Whereas Saini J appears to imply that Lord Sales and Singh LJ’s accounts of the principle of legality are compatible with one another, they in fact present very different visions of the constitutional order. On Singh LJ’s orthodox account, the principle of legality is a mechanism for bringing common law rights and principles, which have a normative existence independent of parliamentary intention, into relationship with statute law. This view accords with that advanced by Robert French, the former Chief Justice of Australia. He has argued (in “The Principle of Legality and Legislative Intention” (2019) 40 Statute Law Review 40) that in light of the “increasing tendency for statute law to infringe upon rights, freedoms and immunities and associated principles of the common law” – a tendency that he identifies in both the UK and Australia – the principle of legality “provides a judicial damage control mechanism which is compatible with representative democracy and the ultimate supremacy of parliament”.
In contrast, the revisionist view transforms the principle of legality by framing it as a device for establishing the “true intention of Parliament” – including by seeking positive evidence that Parliament would support the reading of the relevant provision subject to the right or principle that is in play. On the revisionist view, the principle of legality is no longer concerned with bringing statutory texts into relationship with normatively independent rights and principles that reside in the common law; rather, that binocular view of the constitution is replaced by a monocular view that approaches matters entirely through the lens of actual and supposed parliamentary intention. On this approach, it is necessary to establish not only that Parliament has not excluded the application of relevant constitutional norms but that there is evidence justifying the court in concluding that Parliament intended those norms to apply in the first place.
This goes beyond – and imposes a much higher hurdle than – theoretical accounts of the courts’ public law powers (including the account of the courts’ judicial review powers that I have advocated) that rest simply on the premise that Parliament can and should be taken – absent contrary, clear evidence – to acquiesce in a process of judicial interpretation that renders legislation in terms that align with common law values. Requiring evidence that the specific norm has the requisite level of acceptance among parliamentarians is very different. Indeed, given that the principle of legality is only ever relevant if, in the first place, a court is confronted with legislation that, read literally, appears to undermine a fundamental constitutional norm, it is difficult to see, on the revisionist approach, what scope there could ever be for the principle of legality to operate successfully. After all, the “natural meaning” of the text would presumably make it implausible to conclude that legislators intended it to be subject to the particular norm with which that meaning would be in tension.
It follows that revising the principle of legality so that the principal focus is not on exclusionary legislative intention (“Is the statute so clear as to exclude the possibility of interpreting it compatibly with the relevant constitutional norm?”) but on legislative intention that, in the first place, licenses the interpretive application of the relevant norm amounts to an intellectual move that has the potential to eviscerate the principle of legality. The very evidence of parliamentary acquiescence that is required on this view to trigger the application of the principle of legality is liable, in the first place, to be rendered unavailable by the enactment of legislation whose natural meaning is in tension with the relevant constitutional norm. Far from being “the basic theory underlying the principle of legality”, such an approach stands the principle on its head.
Constitutional revisionism
In a recent post on the Supreme Court’s surprising judgment in Dillon [2026] UKSC 15, Colin Murray refers to that case as an instance of “an intense form of regressive judicial activism at work in UK constitutional law” – an observation that aligns with detailed analysis by Lewis Graham (“Has the UK Supreme Court Become More Restrained in Public Law Cases” (2024) 87 MLR 1073) of contemporary currents in the case law. Ismailov is, regrettably, a further example of what is now a clear trend. At the levels of both constitutional doctrine and constitutional theory, it adopts an approach to the principle of legality that minimises it to an extent that raises the question whether – should this direction of travel be sustained – it can remain a meaningful component of the courts’ constitutional arsenal.
In this regard, Robert French’s framing of the principle as a means of “judicial damage control” is telling. That characterisation of the principle of legality readily acknowledges that the political branches of government are capable of committing acts of constitutional vandalism that the courts have a legitimate role in seeking to contain and correct. As French recognises, that can be done without denying parliamentary sovereignty provided that courts are prepared, should sufficiently clear statutory language be deployed, to accept that the relevant constitutional norm has been legislatively overridden. Such an approach is only possible, however, if the courts are prepared to recognise that the legal constitution has inherent (as distinct from merely legislated) content, including that which exists at common law and to which the principe of legality has traditionally given effect, that sits in relationship – and sometimes in considerable tension – with the output of the legislative process.
The fundamental problem with the view – or, more accurately, one of two conflicting views – apparently endorsed by Saini J in Ismailov is that that very tension is airbrushed away in favour of a conception of the principle of legality, and of the constitution more generally, that focusses on legislative intention to the exclusion of other, normatively independent aspects of the constitutional order. Indeed, the reductio ad absurdum of the position apparently endorsed in Ismailov is that French’s notion of “judicial damage control” becomes oxymoronic because, in the final analysis, there is no independent legal-normative yardstick by which to evaluate legislative interventions in the constitutional sphere – and therefore no sense in which such interventions can occasion constitutional “damage”.
That this framing reduces to a revisionist project is clear from Singh LJ’s lecture to which Saini J refers (with apparent approval). Singh LJ rightly points out that:
It would be a mistake to think that this principle of statutory interpretation was new in the 1990s, even if the phrase “the principle of legality” was. It goes back to cases at least from the time of the First World War, e.g. Re Boaler [[1915] 1 KB 21], where Scrutton J said that, when the legislature has used general words capable of a larger and narrower meaning, those words may be restricted by innumerable presumptions. One of those presumptions was a strict construction of statutes encroaching on rights, especially the liberties of the subject.
The examples can be multiplied – including from well before Re Boaler. Celebrated dicta such as that of Byles J in Cooper v Wandsworth Board of Works (1863) 14 CBNS 180 – according to which even if “there are no positive words in a statute requiring that a party shall be heard, … the justice of the common law will supply the omission of the legislature” – form part of this long tradition. That tradition contrasts sharply with one that requires some form of evidence that the norm being “supplied” is not merely not precluded by the statutory text properly interpreted, but positively supported by the enacting Parliament. Indeed, we can even look back as far as cases like Dr. Bonham’s Case (1610) in which Coke CJ said that “the common law will controul Acts of Parliament, and sometimes adjudge them to be utterly void”. Clearly, the establishment of the doctrine of parliamentary sovereignty in the late 17th century requires such dicta to be reframed, but their relevance now lies in the way they capture the possibility – which still endures – of creative tension between the common law and legislation, the outworking of which today finds expression in the interpretive process.
It is worth concluding by briefly noting the potential future implications of the case law’s present direction of travel in this area. Last year, Lord Briggs gave a lecture placing emphasis on the capacity of the common law to protect fundamental rights. He went as far as to argue that “we should not be unduly fearful about the common law’s ability to cope if, for example, the UK were to repeal the HRA or abandon the Convention”. Commenting on that lecture, I suggested that Lord Briggs might be accused of “misplaced optimism”, given the wider trends discernible in the courts’ public law jurisprudence. That view is reinforced by Ismailov. Should the scenario contemplated by Lord Briggs – namely, ECHR withdrawal and HRA repeal: a policy now advocated by both of the UK’s principal right-wing political parties – eventuate, it will be the common law to which the task of constitutional heavy-lifting falls. But if the direction of travel illustrated by Ismailov is any guide, the common law’s capacity to discharge that role may well turn out to be very limited indeed.
I am grateful to Lewis Graham, Philip Murray and Paolo Sandro for their very helpful comments on an earlier draft of this post.
