25 Therefore, it is necessary to examine whether the nature and purpose of such an agreement enable it to be included in collective negotiations between employers and employees and justify its exclusion, as regards minimum fees for self-employed substitutes, from the scope of Article 101(1) TFEU.

32 As observed by the Advocate General in point 51 of his Opinion, and by the FNV, the Netherlands Government and the European Commission at the hearing, in today’s economy it is not always easy to establish the status of some self-employed contractors as ‘undertakings’, such as the substitutes at issue in the main proceedings.

34 On the other hand, the term ‘employee’ for the purpose of EU law must itself be defined according to objective criteria that characterise the employment relationship, taking into consideration the rights and responsibilities of the persons concerned.

37 In the light of those principles, in order that the self-employed substitutes concerned in the main proceedings may be classified, not as ‘workers’ within the meaning of EU law, but as genuine ‘undertakings’ within the meaning of that law, it is for the national court to ascertain that, apart from the legal nature of their works or service contract, those substitutes do not find themselves in the circumstances set out in paragraphs 33 to 36 above and, in particular, that their relationship with the orchestra concerned is not one of subordination during the contractual relationship, so that they enjoy more independence and flexibility than employees who perform the same activity, as regards the determination of the working hours, the place and manner of performing the tasks assigned, in other words, the rehearsals and concerts.

39 That being said, it must be held that the minimum fees scheme put in place by the provision in Annex 5 to the collective labour agreement directly contributes to the improvement of the employment and working conditions of those substitutes, classified as ‘false self-employed’.