Over recent years, the EU has managed to adopt three important measures on employee participation: the European Works Councils Directive (1994, recast in 2009), the European Company Statute (2001) and the Directive on the Information and Consultation of Employees (2002). While the emergence of forms of ‘soft’ law and ‘multilevel governance’ were preconditions for the adoption of these directives, this article draws attention to the significance of the changing rationales mobilized by the Commission to justify them. Rationales have included company law harmonization; prevention of social dumping; protection of workers’ rights; and participation as a ‘productive factor’. As the EU has widened membership and deepened economic integration, the Commission has sought to demonstrate in particular that employee participation may act as a ‘productive factor’ for companies experiencing business turbulence. Such a rationale, though generally aimed at employers, challenges unions and employee representatives to ensure that the new measures genuinely promote workers’ interests.