The Prime Minister’s recent change to the ministerial code has divided opinion amongst lawyers and academic experts. Prior to the change, the code made reference to “the overarching duties on ministers to comply with the law including international law and treaty obligations and to uphold the administration of justice”. Now, it simply refers to the ministers’ duty to comply with “the law”. The cabinet office denied that the change in wording constituted a change in the content of the duties ministers have and a spokesman stated that the ministerial code still imposed a duty to comply with international law.

Despite these clear statements, most interpreted the change in the wording as having broader legal and political significance. For some, the change put the law right: ministers are bound only by domestic law (the law of the ‘land’) and they cannot have duties of international law, unless these duties have been incorporated into domestic law by an Act of Parliament; on their view, the ministerial code prior to the change was legally inaccurate. For others however, the change severely undermines the Rule of Law: the UK is bound by international law and officials have a duty to comply with it; on their view, the new wording of the ministerial code risks being interpreted as licensing ministers to act against international law, if they are allowed – or even required- to do so by domestic law.

What is this debate about? How can constitutional law experts take radically opposed views on an issue as important as the legal duties of ministers? Of course, as a political issue the controversy makes perfect sense: it is the latest episode in the government’s systematic attack on European and international institutions. Those who oppose the right-wing ideology that informs the government’s xenophobic and isolationist policies, will no doubt condemn the change in the code, whereas those who endorse this ideology will welcome it.

The debate however amongst academic experts appears to be about law and not simply about politics. The two sides to the debate both share the view that the Rule of Law imposes constraints on ministers, but disagree on whether these include standards of international law. Their disagreement is not the result of confusion or ignorance of some constitutional rule or doctrine: it is a genuine disagreement about the value of the Rule of Law itself. It is a disagreement that is both legal and evaluative. So neither side can assume, without begging the question, that the Rule of Law either includes or excludes standards of international law that govern the conduct of ministers.

So what are the arguments in support of the change in the code? In a recent article, John Finnis argues that international treaties binding on the UK, but not incorporated by Parliament, are “no part of the law of the land” and that it is unconstitutional -and hence a violation of the Rule of Law- for Ministers to change the legal rights or obligations of anyone in the UK, simply by entering into or ratifying an international treaty. His argument focuses on treaty obligations of the UK and draws on the well-established doctrine that the executive act of ratifying an international treaty cannot have an automatic effect on domestic law, unless the treaty is transposed into domestic law by an Act of Parliament. This doctrine is underpinned by the constitutional principles of separation of powers and Parliamentary sovereignty: it is for Parliament, and not the executive, to create new legal rights and duties. But the doctrine leaves much unanswered and the argument upon which it is premised is questionable.

First, the old wording of the ministerial code referred not only to treaties, but also to general international law. And international law contains other sources too, such as general principles of law and customary international law. These can be recognized in treaties, but their validity does not derive from the fact that drafters, which is normally the executive branch of states, chose to include them in the text of a treaty. So is customary international law binding on ministers? The proposition that customary international law is automatically part of domestic law, without the need of legislative transposition, has a long pedigree in English law, dating back to 1746 and the case of Triquet v Bath (Roger O’Keefe, ‘The Doctrine of Incorporation Revisited’ in British Yearbook of International Law (2009), p. 12). In 2006, Lord Bingham opined that there is ‘old and high authority’ that this proposition, referred to as the ‘doctrine of incorporation’, is generally true (See R v Jones (Margaret), [2006] UKHL 16; [2007] 1 AC 136, 155 para. 11. To be sure, Lord Bingham qualified the proposition to mean that “customary international law is not a part, but is one of the sources of English law”. And it could be objected, as some scholars have argued (Roger O’Keefe, ibid.), that customary international law is applicable before domestic courts only in so far as – and because – common law so requires. The objection, if correct, would vindicate Finnis’s view that international law is no part of the law of the land: since the applicability of the rules of customary international law depends on the common law, then these rules are (much like the rules of foreign legal systems applicable in conflicts of laws) no part of English law.

But the above objection concedes too much. Saying that common law may make rules of international law applicable does not settle the question of when judges should decide to apply them, as a matter of law. When should common law require the application of rules of international law? If, as is arguably the case, the reason why English courts have a legal duty to give effect to a rule of customary international law relates to the substantive content of that rule (e.g. the fact that aggressive war or genocide are international wrongs), then the common law simply recognizes, rather than creates, the applicability of international law. It is not something courts may choose to ignore, without offending legality. And it would be wrong to say that the basis for why rules of customary international law are applicable is not their substantive content, but the common law doctrine of precedent: why were they applicable in the very first case that domestic courts relied on them?

To insist then that applicable rules of customary international law are “no part of the law of the land”, is misleading. It is to make a point that presupposes a positivistic picture of law, according to which rules are classified on the basis of membership to an order – domestic or international. But this classification is of no normative significance. What matters is the substantive question: do English courts have a legal duty to apply rules of international law, in virtue of the values that international law serves, and irrespective of any rule laid down by Parliament? Whether such rules are “part of the law of the land” is a semantic question that makes sense only if one presupposes a positivist picture of the nature of law; a picture with which natural lawyers like John Finnis would not normally be comfortable.

Second, it is questionable whether even treaty-based obligations must be incorporated by an Act of Parliament for them to have an effect on domestic law. Take the example of the European Convention on Human Rights (ECHR). The UK has been a party to the ECHR for over 60 years and, at until recently, complied with all the judgments of the European Court of Human Rights. This has created legitimate expectations that the UK government will respect the Convention rights and will not seek to undermine the ECHR. Does this fact, rather than the will of the executive, create a legal obligation on ministers to respect the ECHR, which is part of international law?

The constitutional doctrine that Finnis invokes cannot provide answers to the such questions because it is too confined a rule: all it says is that ministers cannot, simply in virtue of ratifying treaties, create legal obligations for people in the UK. Yet, as we saw, the question of whether ministers are legally bound to respect international law is much broader, and more nuanced, than that. So the argument that treaties must be incorporated by an Act of Parliament for them to be part of the law of the land, proves too much. It is also question-begging, since those who argue that international law may have a normative effect on the legal duties of ministers also argue that this is compatible with, indeed required by, the UK Constitution. It is no objection against them to say that, as a matter of plain fact, it is unconstitutional for ministers to be bound by international law directly. For there is no such plain fact: the UK has no written constitution and prominent judges and lawyers disagree on whether ministers can be bound by international law. Lord Bingham, who thought that the old ministerial code was legally binding, was neither confused nor ignorant of constitutional practice.

In a similar vein as Finnis, Richard Ekins and Guglielmo Verdirame argue that “when international law conflicts with domestic law the constitutional principle of the rule of law requires British courts and ministers – and other legal subjects – to follow British law”. But surely this statement is so broad as to make it contested as a matter law. What if Parliament legislates to introduce torture, genocide or aggressive war? Would officials be acting unconstitutionally by refusing to obey, citing international law? Every student of constitutional law is familiar with such thought-experiments. They are meant to challenge the view that Parliamentary sovereignty is self-evidently the ultimate foundation of the Rule of Law in this country, and needs no justificatory support. The view that international law can never trump domestic law, in shaping the duties of ministers, faces the exact same challenge.

Ekins and Verdirame further claim that the principle of the Rule of Law is intimately connected to the institution of the state. But they only offer the linguistic observation that the word ‘state’ figures in translations of the term ‘Rule of Law’ in other languages (État de Droit, Rechtsstaat), an observation that carries little argumentative weight. And in so far as their claim is meant to entail that non-state institutions cannot be Rule of Law-apt, it is manifestly false. The European Union is governed by the value of the Rule of Law, and arguably so are trade unions and self-regulatory bodies like NASDAQ– none of which is a state.

But it seems to me clear what lies underneath all the question-begging legalistic talk of what the UK constitution does or does not allow. Finnis does not like international law (he calls it ‘defective’), because “the criteria for its formation and identification remain opaque, controverted, and manipulable without redress”. He adds that international law “is subject to serious problems of free riding and other forms of bad faith”. Ekins and Verdirame also remark that international law is not institutionalized in the way domestic law is: it has historically been based heavily on treaties, as a way of producing legal binding obligations. Naturally, this often results in a fragmented and heavily politicized set of treaty-based rules. So the worry here seems to me to be this: by making international law binding on them, ministers would be obeying authorities that have nowhere near the same legitimacy as that of the democratically elected UK Parliament and this is morally and politically unacceptable. This, I think, is what best captures the normative basis of their argument. Call this the argument from legitimacy.

The argument from lack of legitimacy is very powerful and is worth careful consideration. It has been challenged extensively in recent literature by the argument that international human rights treaties increase, rather than threaten, the legitimacy of democratic states (see Ronald Dworkin, ‘A New Philosophy of International Law’ (2013) 41 (1) Philosophy & Public Affairs, pp. 2-30). But notice the dialectic of the argument from lack of legitimacy: it suggests that the question of whether (and how) international law standards shape the legal duties of ministers depends on the legitimacy of international law. In other words, and contra Finnis, it is not simply a matter of extracting legal propositions about the Rule of Law by looking only at our own constitutional practice. The question of what offends the Rule of Law in the UK (or any country for that matter) turns in part on the question of whether contemporary international law is legitimate. We have to look outside our borders, so to speak. If the Rule of Law were necessarily a matter of domestic law alone, say because of the doctrine of parliamentary sovereignty, then it would be irrelevant what state international law is in. Yet Finnis does not take it to be irrelevant: he cites what he perceives to be the normative defects of the practice of international law in the course of arguing that the Rule of Law is inherently a matter of domestic law. As I understand his argument, it is the lack of legitimacy that deprives international law a place within the value of the Rule of Law in the UK, and not the fact that it is international. The dialectic of his argument assumes the monism between the domestic and international law that he is so anxious to deny. It assumes that the Rule of Law is the Rule of all legitimate law, regardless of whether it is domestic or international.

This is not the place to defend the claim that many parts of international law are legitimate and hence part of the Rule of Law. But I should like to end by pointing out two misleading assumptions often made in testing this claim. The first is to think of the obligations of international law in a positivistic fashion, as the product of the will of some officials (either those institutions who ratify treaties or the international courts that decide cases). Just like in domestic law, international law contains general principles that are valid, not because some officials endorsed them or pronounced them, but because they fit and justify the practice of the relevant actors. Such principles also shape and constrain the meaning that treaty-based rules have as a matter of international law. And since these general principles are not the product of anyone’s will, but bind in virtue of their moral substance, then the issue of whether they less legitimate than domestic institutions does not even arise. Few would doubt the legitimacy of jus cogens norms or general human rights principles.

It is also wrong to assume that, if an international legal standard is binding on ministers, then the question of whether they complied with international law must always be justiciable before domestic courts. There is no inconsistency in the claim that Tony Blair had a constitutional duty not to start a war that was in breach of international law, but that no domestic court has jurisdiction to hold him into account. Finnis notes in this respect that whether ministers comply with international law is a matter of policy. But it does not follow from the fact that a legal obligation is not justiciable before domestic courts that it is matter of policy. The obligation of ministers to respect international law persists even if domestic courts have no jurisdiction or do not exercise it. There is more to the constitution than what is justiciable before domestic courts.

It is a deeply sad fact about the current political climate in our country that we should have to debate whether our ministers are bound by international standards, many of which have emerged in response to the atrocities of the Second World War and to other shocking incidents of state contempt for individual dignity. And it is perhaps even more sad that this issue is a matter of debate amongst eminent scholars of constitutional and international law.

George Letsas is the Co-Director of the UCL Institute for Human Rights and Professor of the Philosophy of Law at University College London.

(Suggested citation: G. Letsas, ‘The Rule of All Law: A Reply to Finnis, Ekins and Verdirame’ U.K. Const. L. Blog (26th Nov 2015) (available at https://ukconstitutionallaw.org/))