Blog of the International Journal of Constitutional Law

I-CONnect Symposium on “Constitutional Boundaries” — Judging Constitutional Conventions

[Editor’s Note: This is the seventh and final entry in our symposium on “Constitutional Boundaries.” The introduction to the symposium is available here, the first entry is available here, the second entry is available here, the third is available here, the fourth is available here, the fifth is available here, and the sixth is available here.]

Farrah Ahmed, Associate Professor and Associate Dean of Research, Melbourne Law School, Richard Albert, Professor of Law, The University of Texas at Austin, and Adam Perry, Associate Professor in the Faculty of Law and Garrick Tutor and Fellow at Brasenose College, University of Oxford

In this post, we reproduce the abstract and the Introduction to our paper entitled “Judging Constitutional Conventions,” forthcoming in the International Journal of Constitutional Law (ICON). An earlier and unrevised version of this paper is available here. For ease of reading, we have left out the many footnotes that otherwise appear in the Introduction.

Abstract: The study of constitutional conventions is anchored in three assumptions that have so far remained largely unchallenged: that there is a shared “Commonwealth approach” to constitutional conventions; that Commonwealth courts will recognize and employ conventions but never enforce them; and that conventions are always distinguishable from rules of law. We overturn each of these assumptions in this Article. We argue that there is no such shared “Commonwealth approach” to the treatment of constitutional conventions, that Commonwealth courts do, in fact, enforce conventions, and that constitutional conventions have crystallized into law in a major Commonwealth jurisdiction. These insights disrupt much of what is foundational in the study of constitutional conventions.


The late O. Hood Phillips isolated the essential characteristic of constitutional conventions in a simple phrase: “These are not a matter for the courts at all.” Constitutional conventions are commonly described as obligatory but non-justiciable rules that are central to the functioning of government. The scholarly literature takes for granted that there exists a “Commonwealth approach” to how courts understand and in turn treat conventions. Adrian Vermeule, for example, observes that the Commonwealth approach—which “holds that while courts may and should recognise conventions, they may not and should not enforce them”—has “achieved consensus in the United Kingdom and the Commonwealth.” There is a similar consensus that conventions are always distinguishable from rules of law.

In this Article we show that this dominant view is mistaken. We demonstrate, first, that Commonwealth courts go beyond simply recognizing the existence of conventions to employ them in legal reasoning towards the resolution of a dispute. This shows that scholarly claims and their derivative implications about a consistent “Commonwealth approach” to conventions are mistaken. Second, and more significantly, we show that courts do what the dominant view says they cannot: they enforce conventions to resolve legal disputes before them. Finally, we show that we may have found of one of the “holy grails” of Commonwealth constitutional scholarship: a convention that has crystallized into law—something that has until now eluded public law scholars. Future scholarship on constitutional conventions will have to confront our evidence.

We focus on high courts in Canada, India, and the United Kingdom—three Commonwealth jurisdictions with historically shared legal norms around conventions—because their constitutional case law illustrates the range of options available to courts when engaging with conventions. To our knowledge, the recent cases at the core of our analysis have yet to be examined with the comparative and theoretical perspectives we take in this Article. We focus specifically on Miller v. Secretary of State for Exiting the European Union (2017) at the UK Supreme Court, the National Judicial Appointments Commission case (2015) and earlier related controversies at the Indian Supreme Court, as well as the Canadian Supreme Court’s Patriation Reference which is thought to represent—incorrectly, we show—the Commonwealth approach to conventions in courts.

We begin, in Part II, with an inquiry into the ways courts conceivably could engage with conventions. We distinguish specifically among three modes of engagement—recognition, employment and enforcement—as well as the variations within each in order to set the terms for Part III, where we review how Commonwealth courts actually do engage with conventions. We show that high court judgments in Canada, India and the United Kingdom together demonstrate all three of these modes of judicial engagement, suggesting that Commonwealth courts engage with conventions in ways that have until now been undertheorized and underexplored in the scholarly literature. Building on our discussion in Parts II and III, we suggest in Part IV that India may provide the first example of the crystallization of a constitutional convention into law.


Leave a Reply

Your email address will not be published. Required fields are marked *