Environment is a policy field where the role of NGOs is paramount in implementation conflicts. This contribution shows that the Commission has not been able to fully push through its decentralization agenda and environmental NGOs are currently faced with an ambiguous behavior on the part of the Commission with regards to their role in implementation conflicts: on the one hand, the Commission relies on environmental NGOs to discover infringements at national level, but on the other hand, it actively tries to cut them out of any form of involvement in the discussions with the Member States. Similarly, on the one hand, it aims at promoting wide access to justice through the Aarhus Convention and pledging to have the Member States promote it, but on the other hand, through still allowing divergent and restrictive access rules at Member State level, it does not fully live up to its promises.