Remarkably, the interaction between common law and statute has not attracted the scholarly attention it deserves, given that it is such a basic component of legal reasoning in common law systems. This is especially true in the law of employment, where the interaction between common law and statute is a pervasive feature of modern employment law. In recent years, scholars have started to rise to the challenge of developing principles to regulate this interaction, and this article provides a contribution to those debates. It builds upon Lord Hoffmann’s controversial judgment in Johnson v Unisys to identify three modes of interaction: statute as pre-emptive of common law development; statute as an analogical stimulus of common law development; and common law fundamental rights. By connecting this analysis to background principles of legislative supremacy and fundamental rights, it argues that Johnson v Unisys provides an attractive constitutional vision of the relationship between Parliament and the courts.