The case of the British minimum wage illustrates the interplay of ideas and interests in the making of labour legislation. In the 1980s, the pragmatic and data-driven approach of the Cambridge School, associated with the Department of Applied Economics, advanced a case for the minimum wage which combined fairness and efficiency justifications. Through collaboration with trade unions and think tanks, the argument was mobilised into an activist-led campaign which changed political perceptions of the minimum wage. During the 1990s the campaign looked to have failed, as a more conventional economics informed the passage of the National Minimum Wage Act 1998. In the long run, however, the case made by the Cambridge School has endured, to inform today’s global movement for a living wage.