As regards a question referred for a preliminary ruling on the interpretation of Directive 2004/18 on the coordination of procedures for the award of public works contracts, public supply contracts and public service contracts, even if the public contract at issue is of a lower value than the relevant threshold of that directive, it is appropriate to consider that the procedure for the award of the public contract at issue is none the less subject to the fundamental rules and the general principles of the FEU Treaty, in particular the principles of equal treatment and of non-discrimination on grounds of nationality and the consequent obligation of transparency, since the referring court accepts the application to the dispute before it of the principles of EU law and notes, in that context, the existence of certain cross-border interest.

The fact that the national court’s question refers only to certain provisions of EU law does not mean that the Court may not provide the national court with all the guidance on points of interpretation that may be of assistance in adjudicating on the case pending before it, whether or not that court has referred to those points in its question. It is, in this regard, for the Court to extract from all the information provided by the national court, in particular from the grounds of the decision to make the reference, the points of EU law which require interpretation in view of the subject matter of the dispute.

The fundamental rules and general principles of the FEU Treaty, in particular the principles of equal treatment and of non-discrimination and the consequent obligation of transparency, must be interpreted as not precluding a provision of national law under which a contracting authority may provide that a candidate or tenderer be automatically excluded from a tendering procedure relating to a public contract for not having lodged, with its tender, a written acceptance of the commitments and declarations contained in a legality protocol the purpose of which is to prevent organised crime from infiltrating the public procurement sector. However, inasmuch as that protocol contains declarations that the candidate or tenderer is not in a relationship of control or of association with other candidates or tenderers, has not concluded and will not conclude any agreement with other participants in the tendering procedure and will not subcontract any type of tasks to other undertakings participating in that procedure, the lack of such declarations is not to lead to the automatic exclusion of the candidate or tenderer from that procedure.

As regards the principles of equal treatment and transparency, the Member States must be recognised to have a certain discretion for the purpose of adopting measures intended to ensure observance of those principles, which are binding on contracting authorities in any procedure for the award of a public contract. Each Member State is best placed to identify, in the light of historical, legal, economic or social considerations specific to it, situations propitious to conduct liable to bring about breaches of those principles. However, in accordance with the principle of proportionality, which constitutes a general principle of EU law, a measure such as the obligation to declare acceptance of a legality protocol must not go beyond what is necessary to achieve the intended objective. In that regard, the automatic exclusion of candidates or tenderers who are in a relationship of control or association with other candidates or tenderers goes beyond what is necessary to prevent collusive behaviour and, therefore, to ensure the application of the principle of equal treatment and observance of the obligation of transparency. Such an automatic exclusion constitutes an irrebutable presumption of mutual interference in the respective tenders, for the same contract, of undertakings linked by a relationship of control or of association. Accordingly, it precludes the possibility for those candidates or tenderers of showing that their tenders are independent and is therefore contrary to the EU interest in ensuring the widest possible participation by tenderers in a call for tenders.

(see paras 26, 29, 36, 41, operative part)