For much of the twentieth century, a functionalist style of scholarship emerged as a critical and dissenting tradition in British constitutional thought. Many of its animating concerns were expressed in J. A. G. Griffith’s famous lecture, ‘The Political Constitution’. This article situates Lord Wedderburn’s work on collective labour law within the broader tradition of political constitutionalism at the London School of Economics. Lord Wedderburn’s intellectual journey in labour law was concerned with the political nature of legal discourse, and the emancipatory potential of fundamental rights discourse as a way of achieving democratic freedoms for working people. The article examines the shifts in Wedderburn’s attitude towards the human rights paradigm, in the light of his passionate commitment to the primacy of politics in the sphere of labour law. In so doing, it concludes with an affirmation of Lord Wedderburn’s remarkable intellectual legacy in framing the virtues and limitations of a ‘political constitution’ for working people.