Conor McCormick: Debating Constitutional Dualism

Conor McCormickA recent amendment to the Ministerial Code has prompted some interesting constitutional commentary which focuses mainly on the perceived rationale behind the change and the critical response of some to its legal validity. The revised document does not make specific reference to international law and treaty obligations in its exposition of an overarching duty on ministers to comply with the law. This post takes that amendment as its starting point for a brief analysis of the apparently contrasting conceptions of international law and treaty obligations prevalent between some actors within the executive and the judiciary, with unincorporated international treaties as its focus. On one view, the newly drafted Ministerial Code suggests that members of the current executive seek to reaffirm dualism, the theory that denies judicial authority to enforce international treaties entered into by the executive until legislation to give domestic effect to the treaty is made, as an implicit constitutional fundamental of the UK. In contrast, the recent judicial pronouncement by a dissenting Lord Kerr in R (SG & Ors) v Secretary of State for Work and Pensions [2015] UKSC 16 challenges that view explicitly by considering an unincorporated international treaty provision ‘directly enforceable in UK domestic law’, albeit as an exception to dualist theory for human rights related treaties only. This discord highlights the tension between constitutional orthodoxy and innovation at the highest levels of law and politics in the UK, inviting a closer examination of the theoretical underpinnings of dualism and its continuing role in the UK’s constitutional order.

Leaving to one side the domestic status and relevance of customary international law, as well as direct and indirect incorporating statutes, the orthodox position in respect of unincorporated international treaties is a good starting point for examining the contest between different conceptions of international law under the constitution of the UK more generally.

The orthodox position is that unincorporated international treaties (which includes agreements, charters, conventions, covenants, declarations and protocols) are non-justiciable and lack direct effect in domestic law (see the forceful opinion by Lord Oliver in support of this view in J H Rayner (Mincing Lane) Ltd v Department of Trade and Industry (“International Tin Council”) [1990] 2 AC 418). Treaty-making is a royal prerogative power exercisable by the executive. This is the case because it is the executive that is bound by treaties under international law. When an authorised member of the UK government signs a treaty, the state is not obliged to ratify it (although Foreign and Commonwealth Office guidance states that the UK does not sign a treaty unless it ‘has a reasonably firm intention of ratifying’). In fact, it is now a statutory requirement that parliamentary approval must be obtained before a treaty is ratified (or acceded to) under the terms of the Constitutional Reform and Governance Act 2010, Part 2. With certain exceptions, those provisions require the executive to give reasons why it wishes to ratify a treaty if Parliament passes a resolution objecting to ratification. They further enable the House of Commons to block a treaty indefinitely (whereas the House of Lords cannot do so on its own). In essence, the orthodox position normally affords Parliament the last word on whether a particular treaty will have domestic effect. Thus, in the absence of some form of parliamentary approval, international treaties remain unincorporated in domestic law and therefore unenforceable by domestic courts. This conception allows the separation of powers underlying the doctrine of parliamentary sovereignty to be preserved, while making it possible for the UK as a nation State to place itself in breach of international obligations in the event of failure by the executive to secure parliamentary approval for the incorporation of treaty obligations it has agreed to by signature or otherwise. As Lord Diplock put it in Salomon v Commissioners of Customs and Excise [1967] 2 QB 116, ‘the sovereign power of the Queen in Parliament extends to breaking treaties’.

In what appears to be a reaffirmation of this dualist conception of international law, what was previously a codified overarching duty on UK Government Ministers ‘to comply with the law including international law and treaty obligations’ (emphasis added) has been abbreviated by the Cabinet Office to an overarching duty on Ministers ‘to comply with the law’. As mentioned at the outset, there are different views as to the rationale and validity of this amendment. Some view it as an attempt by the Government to lobotomise internationally agreed obligations on the State, while others have dismissed it as a mere linguistic simplification lacking any important consequences (especially given that it is not a legally binding document). My own view is that the amendment, while being no less accurate a reflection of the obligations upon ministers under domestic and international law (as Mark Elliott has explained), only invites speculation about whether it was motivated by the Conservative Government’s political aim of reclaiming title to the UK’s sovereign power over international law institutions in the domestic setting. Nonetheless, given that both law and politics inform constitutional development in the UK, the amendment appears to be significant.

The orthodox position set out above can be contrasted with a conception of the normative force of certain unincorporated international treaty provisions developed in a constitutionally innovative line of case law, culminating in the recent pronouncement, noted above, by a dissenting Lord Kerr in R (SG & Ors) v Secretary of State for Work and Pensions [2015] UKSC 16. Lord Kerr’s opinion referenced the non-justiciability of international treaties and their lack of direct effect as ‘a matter of constitutional orthodoxy’ underpinned by court decisions refusing to give effect to the European Convention of Human Rights before the coming into force of the Human Rights Act 1998 (the leading authority in that line of precedent being R v Secretary of State for the Home Department, ex p Brind [1991] 1 AC 696). However, Lord Kerr’s opinion proceeded to suggest that not only is prerogative power no longer categorically immune from judicial review (see Council of Civil Service Unions v Minister for the Civil Service [1985] AC 374), but that ‘the seemingly comprehensive ban on the use by the courts of unincorporated international treaties to recognise rights on the domestic law plane’ (as held in R (Campaign for Nuclear Disarmament v Prime Minister of the United Kingdom [2002] EWHC 2759, 126 ILR 727) is undermined by three judicial doctrines which arguably enable such treaties to have an impact on national law.

First, because there is a strong presumption in favour of interpreting domestic legislation in a way which does not place the UK in breach of its international obligations, UK courts may have regard to unincorporated international treaties as an aid to statutory interpretation. Indeed, Lady Hale’s dissenting judgment in R (SG & Ors) v Secretary of State for Work and Pensions [2015] UKSC 16 enabled her to reach the same conclusion as Lord Kerr on the issue before the divided Supreme Court without regarding the relevant unincorporated international treaty (the United Nations Convention on the Rights of the Child) as directly enforceable. Instead, Lady Hale held that the court should have regard to the treaty as an aid to the construction of ECHR jurisprudence which has been incorporated via the Human Rights Act 1998 (referring to Burnip v Birmingham City Council [2012] EWCA Civ 629).

Second, unincorporated international treaties may have a bearing upon the judicial development or clarification of ambiguity in the common law. Lord Kerr went so far as to say that where there is doubt about the content of the common law, it may not only be appropriate to consider such treaties to determine what the common law position interpretatively is, but also to determine what it normatively should be. At the same time, Lord Kerr further reasserted the proposition based on A v Secretary of State for the Home Department (No 2) [2004] EWCA Civ 1123; [2005] 1 WLR 414 that the common law cannot be used to incorporate treaties ‘through the back door’.

Third, the courts may hold that the entering into a treaty by the executive could give rise to a legitimate expectation because, subject to any indication to the contrary, ratification may amount to a representation that it will act compatibly with obligations imposed on it by the treaty in question. While noting, perhaps euphemistically, that this proposition is at the least ‘controversial’, Lord Kerr appears to have relied on it to base his development of an exception to the general principles in favour of non-justiciability and against direct enforceability in relation to unincorporated international human rights treaties. Lord Kerr rested his argument mostly on academic criticisms about adherence to the dualist theory of international law in relation to human rights conventions, together with Lord Steyn’s unambiguous doubts about same expressed as follows in Re McKerr [2004] UKHL 12:

The rationale of the dualist theory, which underpins the International Tin Council case, is that any inroad on it would risk abuses by the executive to the detriment of citizens. It is, however, difficult to see what relevance this has to international human rights treaties which create fundamental rights for individuals against the state and its agencies.

Having acknowledged the ‘somewhat absolutist position’ taken by opponents of this view, Lord Kerr expressed his agreement with Lord Steyn’s analysis by holding that, if the rationale for the dualist theory is to protect UK citizens from abuses by the executive, it is not easy to justify refusing to recognise human rights enshrined in an international treaty to which the executive has subscribed as directly enforceable. This account ostensibly overlooks the fundamentality of parliamentary approval, which is normally deemed necessary in order to maintain parliament’s sovereign position in the constitutional order of the UK. It also skews the traditional understanding of the rationale for the dualist theory, which is the supremacy of domestic law. Thus, Lord Kerr’s conception of unincorporated international human rights law implies that the executive is not constitutionally prevented from unilaterally binding itself to act in accordance with international human rights law standards, and refutes the existence of any logical reason to deny judicial enforcement of same. It is on this basis that Lord Kerr considered that a provision of the United Nations Convention on the Rights of the Child was directly enforceable in domestic law. However, as a dissenting opinion, Lord Kerr’s preferred conception does not overrule the House of Lords’ decision in R v Director of Public Prosecutions, ex p Kebliene [2000] 2 AC 326 (HL) which set a precedent for the proposition that a legitimate expectation cannot be based on the ratification of a treaty.

Although Lord Kerr’s innovative conception of unincorporated international human rights treaties is a minority view on the Supreme Court at present, its potential significance should not be underestimated at a time when constitutional orthodoxy is being subjected to continuous scrutiny and debate. Indeed, this view could attract greater attention in the near future depending on how the Government’s plans for reforming the domestic application of international law transpire. It is in this context that the recently amended Ministerial Code should be considered, for it suggests that the executive supports, in concert with John Finnis, maintaining the orthodox relationship between international law and the UK constitution.

Conor McCormick is a PhD student in the School of Law at the Queen’s University of Belfast. The author is grateful to Professor Gordon Anthony for suggesting several improvements to an earlier draft of this post.

(Suggested citation: C. McCormick, ‘Debating Constitutional Dualism’ U.K. Const. L. Blog (24th Nov 2015) (available at