A total of nineteen Chambers have sent a Reasoned Opinion to the European Commission, stating that they found a breach of the principle of subsidiarity. This is the second time ever the threshold for a yellow card was reached: the first time was for the Monti II proposal.

The EPPO proposal is part of a package which includes proposal COM (2013) 535 for a Regulation of the European Parliament and of the Council on the European Union Agency for Criminal Justice Cooperation (Eurojust).

In the case of a proposal for a legislative act submitted on the basis of Art. 76 TFEU (Area of Freedom, Security and Justice), the threshold to trigger the Early Warning System (EWS) is a quarter of the total amount of votes allocated to the national Parliaments or Chambers (unicameral parliaments have 2 votes, while in bicameral parliaments, every chamber has 1 vote).

After the services of the European Commission have established that the conditions for triggering the EWS are met, the College of Commissioners will decide on the future course of action and inform the parties involved. The Commission may decide to maintain, amend or withdraw the draft and she must give reasons for this decision.