Art. 171. Procedural guarantees in award criteria

1. Concessions shall be awarded on the basis of the award criteria set out by the contracting authority or entity in accordance with Article 173, provided that all of the following conditions are fulfilled:

a) the tender complies with the minimum requirements set out by the contracting authority or entity;

b) the tenderer complies with the conditions for participation as referred to in Article 172;

c) the tenderer is not excluded from participating in the award procedure in accordance with Article 172.

2. The minimum requirements referred to in point 1, letter a) shall provide for conditions and technical, physical, functional and legal characteristics that any tender should meet or possess.

3. The contracting authorities or entities shall also provide:

a) in the concession notice, a description of the concession and of the conditions of participation;

b) in the concession notice, in the invitation to submit a tender or in other concession documents, a description of the award criteria and, where applicable, the minimum requirements to be met.

4. The contracting authority or contracting entity may limit the number of candidates or tenderers to an appropriate level, on condition that this is done in a transparent manner and on the basis of objective criteria. The number of candidates or tenderers invited shall be sufficient to ensure genuine competition.

5. The contracting authority or entity shall communicate to all participants the modalities of the procedure and an indicative completion deadline. Any possible modification shall be communicated to all participants and, to the extent that they concern elements disclosed in the concession notice, advertised to all economic operators.

6. The contracting authority or entity shall ensure the traceability of the acts concerning every single stage of the procedure using the means it judges appropriate, subject to compliance with Article 53.

7. The contracting authority or entity may freely hold negotiations with candidates and tenderers. The subject-matter of the concession, the award criteria and the minimum requirements shall not be changed during the course of the negotiations.