The Council is too often depicted as the battleground for intermittent clashes between national ministers. Based upon case studies of legislation produced in five ‘First Pillar’ sectors, the research presented here has explored the submerged, and much larger, part of this institutional ‘iceberg’: Council working groups. It does so by examining how members of these entities interact with civil servants in COREPER and ministers, on the one hand, and representatives of the Commission and the European Parliament, on the other. Contrary to many practitioner or formalist accounts, the principal finding is that working groups do not operate solely on a ‘technical level’. Instead, they are vital arenas through which the ambiguous nature of politics in the European Union heavily influences negotiating processes and legislative outcomes.