In July 2013 the European Commission put forward a proposal to establish a European Public Prosecutor's Office. The European Public Prosecutor’s Office would be a judicial body in charge of investigating, with the power to order national police forces to initiate investigations, assembling all the evidence in favour or against the accused and responsible for conducting and coordinating prosecutions. Moreover, he/she would have the power to bring to judgment perpetrators, and accomplices, of offences against the Union’s financial interests, deciding in which Member State the trial will take place. The EPPO jurisdiction would prevail over the jurisdiction of the Member States enforcement authorities. The creation of such a post is being made in complete disregard of the different legal systems within the EU and it is likely to have a severe impact on Member States criminal systems. In fact, the Commission’s proposal breaches the subsidiarity principle.

Under the Protocol on the Application of the Principles of Subsidiarity and Proportionality, National Parliaments may submit, within eight-weeks, from the date of transmission of the legislative proposal, to the Presidents of the European Parliament, the Council and the Commission, a “reasoned opinion stating why it considers that the draft in question does not comply with the principle of subsidiarity.” Then, if one-third of national parliaments object to a legislative proposal, on subsidiarity grounds, the draft must be reviewed. The threshold for a ‘yellow card’ has been exceeded in the case of the European public prosecutor however the EU institutions are only required to take account of the national parliament's reasoned opinions. The Commission “may decide to maintain, amend or withdraw the draft.” Thus, it is free to retain the proposal. In the case of the European public prosecutor, the Commission has completely ignored the yellow card and decided to go ahead.

National parliaments have shown their opposition to this proposal, which was then ignored. This clearly shows the lack of democratic control over the Commission.

On 3 March the Council held a policy debate on the European Commission's proposal to establish a European Public Prosecutor's office. For the first time, the ministers of justice expressed their views on the proposal, including the structure of the Office, the division of tasks and on the regime of procedural rights applicable to suspects and victims. Whereas under the Commission’s proposal the European Public Prosecutor would be appointed at European level and would lead the EPPO and give instructions to European Delegated Prosecutors based in member states the majority of member states believes that the EPPO must be organised around a College representing participating member states. The European Commission wants to give the EPPO exclusive competence for all offences against the Union's financial interests but some member states want to retain at least some minor offences to be prosecuted at national level.

On 12 March, the European Parliament endorsed the Commission proposal for a European Public Prosecutor’s Office. After obtaining the consent of the European Parliament, in order to become law, the Commission's proposal now needs to be unanimously adopted by Member States in the Council. However, the veto of one or more Member States will not be enough to stop the establishment of a European Public Prosecutor's Office, as under the Treaties, if the European Council is unable to find an agreement, nine member states may establish ‘enhanced cooperation’, on the basis of the draft regulation, in question, a notification to the European Parliament, the Council and the European Commission will be enough. It is important to recall that eleven EU member states, including Cyprus, the Czech Republic, France, Hungary, Ireland, Malta, the Netherlands, Romania, Slovenia and the UK, had sent reasoned opinions against the proposal nonetheless the European Comission said “the national Parliaments of a clear majority of Member States have not issued reasoned opinions and can thus be counted among the probable participants to the European Public Prosecutor's Office.” Hence, the non-participating States cannot prevent the others to go ahead with further integration.

The UK Government has decided not to opt in to the European Commission’s proposal establishing the EPPO. As the Parliamentary Under Secretary of State for Security, James Brokenshire, stressed the proposal challenges “some of the fundamental principles and aspects of our criminal justice system.”

It is important to mention that the Lisbon Treaty provides for the extension of powers of the European Public Prosecutor’s Office to include “serious crimes having a cross-border dimension.” In fact, according to the EUObserver Giovanni Kessler, head of the EU anti-fraud office Olaf has already said “If this EPPO [European Public Prosecutor Office] starts working well, [it] will possibly, probably expand to other competences, to the others crimes, which are by nature transnational”.