The activity of workers' organizations and labour issues is once again on the international relations agenda in fields ranging from labour standards at the WTO, to the terms of regional integration, to corporate codes of conduct, to civil society coalition building. This article argues that the role of the international union movement is transforming from a supporter of US capitalism to a brake on neoliberal industrial relations, to potentially advocating a different form of political economy in alliance with other groups. This transformation has taken place partially because unions have has been expelled from the corridors of power in key states and partially because of their encounter with a series of social movements. The cases of the ICFTU's activity in engaging international organizations and MNCs are used as examples to illustrate this trend. The implications for activity in, and the theory of, the global political economy are potentially significant.