The European Union (EU) is an evolving system of multi-level governance (MLG). For scholars of the EU, a critical question is which level of governance has the most decisive influence on the integration process? Some studies of EU regional policy claim that subnational actors, using channels of interest representation that bypass national officials, interact directly with EU policy-makers generating outcomes that are neither desired nor intended by national executives. This article examines the development of EU biodiversity policy over a thirty-year period (c. 1970-2000) and finds that environmental groups, who were generally marginalized at the national level in Britain, have learnt to use EU opportunities to outflank the government, resulting in policy outcomes that they would be unlikely to secure through national channels of representation. However, the evidence presented suggests that supranational actors were the major cause of these unintended consequences, not environmental groups.