Why should European Works Councils (EWCs) discuss the International Labour Organisation's core labour standards? With respect to their legal duties, EWCs are information and consultation bodies on European topics. In practice, they can become main actors in negotiating and implementing international framework agreements (IFAs) about core labour standards in multinational companies. Using theoretical models of internal and inter-organizational bargaining, the author highlights the role of those European bodies that work together with Global Union Federations (GUFs) during negotiations. In order to analyse the different forms of actors' involvement in negotiations, empirical data from a content analysis of all IFAs, as well as three company case studies, will be presented. It will be argued that internal bargaining between EWCs and GUFs influences negotiations with management. Furthermore, the article discusses the role of norms and institutions that shape internal as well as inter-organizational bargaining processes, and lead to different forms of involvement of employee representation bodies.