The Theory and Doctrine of Unconstitutional Constitutional Amendment in Canada

It has become increasingly common for courts in constitutional democracies to invalidate constitutional amendments. Courts have enforced both written and unwritten limits on how political actors may exercise the formal amendment power. They have relied either on constitutional texts that expressly entrench provisions against formal amendment or on their own interpretation of these texts as implicitly establishing an unalterable constitutional core. Although the Supreme Court of Canada has not yet invalidated a constitutional amendment, modern case law provides the constitutional basis for the Court to declare that a future constitutional amendment violates either the text or spirit of the Constitution of Canada. In this Article, I trace the origins and evolution of the theory and doctrine of unconstitutional constitutional amendment, I explain how the theory and doctrine may apply today in Canada, and I suggest a detailed framework to evaluate when and how the Supreme Court of Canada may exercise the extraordinary residual constitutional authority to invalidate a constitutional amendment.