The author submits to a critical analysis the sentence no. 231/2013 of the Corte costituzionale, concerning the discipline of the rappresentanze sindacali aziendali (union representatives at workplace level) established by art. 19 of the Statuto dei lavoratori. After briefly illustrating the context which has originated the issue of constitutionality, the author dwells on the recent history of art. 19, following the 1995 referendum. The author agrees that the criterion under which the unions entitled to constitute Rsa were exclusively those which had signed collective agreements applied in the work unit was not reasonable, as it harmed unions expressing dissenting positions. He observes, however, that also the new criterion individuated by the court - centred on the active participation of a union to the collective bargaining - may not resolve every problem. Anyway, the discussed topic is only an aspect of a broader problem regarding the necessity of new rules for the Italian industrial relations.