Canadian constitutional jurisprudence might, perhaps unexpectedly, shed some light on the process set in motion by the referendum regarding the United Kingdom’s exit from the European Union, a leading feature of which is the absence of clear answers to important constitutional questions. Of course, we must mind the gap between the two countries’ constitutions, which are often contrasted on the basis that one is written and federal and the other lacks those two defining features. Yet, Canada has been regularly faced with situations about which its written constitution was silent. The Supreme Court of Canada was asked on several occasions to fill the gap and to settle controversies between political actors. The Court’s decisions illustrate what kind of constitutional reasoning can be deployed to that end and teach a number of substantive lessons about the political principles that suffuse constitutional law. The principles laid out by the Court may enrich the discussion about, for example, who can trigger the Article 50 process or whether Scotland must consent to the Brexit process.

That string of Supreme Court of Canada decisions begins with the Patriation Reference, in which the Court declared a constitutional convention to the effect that the federal government could not secure a constitutional amendment from Westminster without the support of a substantial majority of provinces. Some twenty years later, in the Quebec Secession Reference, it decided, among other things, that Quebec’s secession from Canada would require a formal amendment of the Canadian Constitution, and it laid out the basic features of the process that would follow a vote for independence. More recently, the Senate Reform Reference dealt with the federal government’s attempt to provide, amongst other things, for the election of Senators (who are currently appointed).  The Court held that this cannot be done without a formal amendment of the Constitution, requiring the consent of a qualified majority of provinces. And in the Supreme Court Act Reference, the Court stated that a constitutional amendment was necessary in order to change the eligibility requirements for the three of its nine judges who, by statute, are required to come from Quebec, which has a civil law system.

In those four cases, there was no explicit constitutional provision prohibiting what was envisioned by, in the relevant circumstances, the federal government or the Quebec government.  British jurists are familiar with constitutional conventions, the conceptual tool employed by the Court in the Patriation Reference. In that case, the Court found that the federal government had always felt bound to secure provincial support before requesting an amendment to the Canadian constitution (a British statute which, at that time, did not contain provisions for its amendment by Canadian authorities). Hence, while there was no legal impediment to federal unilateral action, this would have been unconstitutional in the conventional sense. Following the Court’s ruling, the federal government returned to the bargaining table and obtained the consent of all provinces except Quebec.

The lack of precedents made it more difficult to rely on constitutional conventions to decide the other three cases. Instead, the Court employed “structural” or “principle-based” reasoning to extend the meaning of existing constitutional provisions or to provide guidance where the text is lacking.

In the Secession Reference, the Court highlighted four “underlying” principles of the Canadian constitution, namely democracy, federalism, constitutionalism and the rule of law, and the protection of minorities. These principles may assist in the interpretation of the text of the constitution, but they also guide its development and evolution and, in certain circumstances, may give rise to substantive legal obligations.

In the Senate Reform Reference, the Court insisted on the constitution’s “architecture” or “basic structure.” The Senate, and its unelected character, was an integral part of this architecture. It followed that this architecture could not be altered without a constitutional amendment, even if Parliament tried to accomplish its goal through means not expressly prohibited by the constitutional text. Moreover, the Court stated that the Senate could not be abolished without the consent of all provinces, even though the amending formula nowhere mentions this possibility.

The concept of “historic bargain” played a crucial role in the Supreme Court Act Reference. The creation of the Supreme Court in 1875 was described as such a bargain, through which Quebec obtained the guarantee of a fixed number of seats on the Court. Likewise, the adoption of a procedure to provide for the amendment of the constitution in Canada (the so-called “patriation” of the Constitution), in 1982, was described as a bargain between the provinces and the federal government, which, among other things and perhaps counterfactually, was aimed at protecting Quebec’s interest in protecting its representation on the Supreme Court.

It should be noted that in order to identify the underlying principles, basic architecture and historic bargains, the Court looked beyond the constitutional text and into the country’s history and political relations.

Beyond the types of arguments on which they were based, these cases also provide some guidance on issues that arise in the wake of the Brexit referendum. I do not profess to have detailed knowledge of those issues, so I will simply try to sketch how Canadian law might support arguments made in those debates.

One question that is highly controversial is whether the executive alone may trigger the Article 50 process towards leaving the EU. In the Secession Reference, the Supreme Court of Canada was faced with a somewhat similar issue. It was said that Canada (that is, the federal government) could consent alone to Quebec’s secession, because this would be an international agreement regarding Canada’s borders. Yet, the Court said that secession required a constitutional amendment, as it would “alter the governance of Canadian territory in a manner which undoubtedly is inconsistent with our current constitutional arrangements” (at para. 84). This is in line with the general tendency, in the four cases studied, to require broad support before enacting major constitutional changes.

But can that broad support be expressed in a referendum? The argument in the Secession Reference was that a majority vote of the Quebec population in favour of independence would allow Quebec to disregard the existing Canadian constitutional arrangements. But the Court said that democracy was only one of the relevant principles. It observed that following such a referendum, the will of “two legitimate majorities” (para. 93) would need to be reconciled, and the outcome would be the product of negotiation, not one majority trumping the other. In saying this, the Court was combining the democratic principle and the federalism principle. As I have argued elsewhere, the Court’s decisions embody a “compact theory” vision of the Canadian constitution, according to which the Constitution must be seen as the result of agreements between the country’s constituent units. Accordingly, the constitution must be interpreted in a way that gives effect to those historic bargains rather than one that would result in their breach, even though the latter would be the outcome of a narrow textual interpretation.

More generally, the Secession Reference appears to be based on a polycentric view of politics, according to which political relationships are just as important as the exercise of sovereignty. In other words, the expression of the “sovereign will” of one party to a relationship is not sufficient to change that relationship. Thus, according to the democratic principle, “considerable weight” must be given to the expression of the will of a province’s population to secede; this would trigger an obligation on the part of the other components of the federation to negotiate; but the outcome could be something other than independence (at paras. 91, 96).

These brief remarks do no do justice to the Court’s complex and nuanced opinions. But it is apparent that the principles identified by the Court could apply, first at the level of the negotiations between the United Kingdom and the European Union, and second, within the United Kingdom. A few words about the latter possibility are in order.

While the United Kingdom constitution is largely unwritten, it also includes legislation, which could call for interpretive methods similar to those applied to the Canadian written constitution. This is especially true where that legislation is of a constitutional nature and embodies fundamental agreements between the country and its constituent parts, for example Scotland or Northern Ireland. As I mentioned above, the Supreme Court of Canada adopted a generous interpretation of constitutional provisions, and arguably filled gaps in the constitutional text, to ensure that those “compacts” or “historic bargains” between the country’s constituent parts are upheld.

Transposed to the United Kingdom, this line of reasoning could lead to the result that the fundamental characteristics of the Union cannot be altered without the consent of the constituent units. With respect to Scotland, the first step of the argument would be that section 1 of the Scotland Act 2016 implicitly lays out a “manner and form” requirement, that is, a procedure that the UK Parliament must legally follow before “abolishing” Scottish institutions. The second step would be to argue, based on Canadian-style structural arguments, that “abolition” does not mean only abolition stricto sensu, but also any major change to the basic elements of the “bargain” between Scotland and the United Kingdom. I will leave it to others to flesh out the third step, namely that continuing membership in the European Union was a basic – even if unwritten – tenet of the arrangement between Edinburgh and London, possibly based on the history of the discussions leading to Scottish devolution, the arguments made during the 2014 referendum campaign or various provisions of the Scotland Act 1998 (as amended) that assume EU membership. If these premises are accepted, Parliament would be prohibited to enact such major change without the consent of the Scottish people expressed in a referendum. Note that the foregoing argument is based on law and not convention, much like the Senate Reform Reference and the Supreme Court Act Reference.

One may have the impression that “structural” or “principle-based” constitutional interpretation is too far removed from British tradition and its focus on Parliamentary supremacy. Nevertheless, the Supreme Court of Canada’s decisions at the very least express basic principles of political morality, which, whatever their legal status (and justiciability), are highly relevant in the current debate. And even in the realm of strict law, we must not forget that the Canadian constitution is, in origin, a British statute and that it is a British Court (the Privy Council) that said, almost one century ago, that it had to be interpreted like a “living tree…”

Sébastien Grammond, Professor, University of Ottawa

The author thanks his colleagues Peter Oliver and Pierre Thibault, who offered comments on earlier versions of this post.

(Suggested citaiton: S. Grammond, ‘Canadian Constitutional Jurisprudence and the Brexit Process’, U.K. Const. L. Blog (12th Jul 2016) (available at https://ukconstitutionallaw.org/))