In its 13 December judgment in the Forposta Case, the ECJ interpreted the concept of "grave professional misconduct" within the meaning of Article 45(2)(d) of the General Public Procurement Directive 2004/18/EC.

Article 45(2)(b) of the Public Procurement Directive provides for a limitative list of grounds for exclusion. This provision has been implemented for the Netherlands in Article 45(3) of the Public Procurement Decree (Besluit aanbestedingsregels overheidsopdrachten) and has also been laid down in Article 2.87(1) of the Public Procurement Act 2012 (Aanbestedingswet 2012), which is to replace the Decree in early 2013. One such ground for exclusion is the ground sub (d), which relates to the situation where the undertaken concerned "has been guilty of grave professional misconduct proven by any means which the contracting authorities can demonstrate".

The provision does not give a definition of the concept of "grave professional misconduct". In practice, questions regularly arise on the relation between this ground for exclusion on the one hand and the ground sub (c) on the other, the latter relating to the situation where the undertaking "has been convicted by a judgment which has the force of res judicata in accordance with the legal provisions of the country of any offence concerning his professional conduct". Similar grounds for exclusion are laid down in the EU Financial Regulation, which applies to procurements by the EU institutions. As far as the central Dutch government is concerned, i.e. ministries and central agencies, these concepts have been defined in the 2004 Policy rules on integrity and exclusion in sensitive sectors (Beleidsregels integriteit en uitsluiting bij aanbestedingen in BIBOB-sectoren, Official Gazette Stcrt. of 27 February 2004, No 40, p. 15), which define as "grave professional misconduct", inter alia, bribery, the drawing up of false documents, misrepresentation, the endangering of employees and the finding of a cartel infringement.

In the Forposta Case, the Polish postal service incumbent Poczta Polska had excluded Forposta from a public procurement procedure because it had previously terminated an agreement with Forposta for breach of contract and because the Polish public procurement rules provide for mandatory exclusion when the contracting authority has terminated a contract with the undertaking concerned in the last three years on grounds of breach of contract in relation to at least 5% of the contract value concerned.

Further to a preliminary reference from the Polish Court, the ECJ holds that the concepts of "grave", "professional" and "misconduct" can be can be specified and explained in national law, provided that it has regard for EU law. According to the ECJ, said concepts encompass any wrongful conduct which has an impact on the professional credibility of the operator at issue and not only the violations of professional ethical standards established by a disciplinary body or by a judgment which has the force of res judicata. It follows that breach of contract can indeed be considered as professional misconduct, it being understood that the concept of "grave misconduct" normally refers to conduct which denotes a wrongful intent or gross negligence, which means that not any breach of contract automatically amounts to grave misconduct: this must be assessed on a case by case basis.

It can be inferred from this judgment that contracting authorities have a relatively large margin of appreciation when assessing which type of behaviour amounts to grave professional misconduct, including relatively grave breaches of contract, but that they must do so on a case by case basis, in light of the proportionality principle.