An arbitration clause that devolves cognizance of disputes to an arbitral tribunal with a mandate to judge according to equity is null and void when one of the parties to the relationship is a public administration, by reason of conflict with the principles of legality, impartiality and proper conduct of administrative action referred to in Article 97 of the Constitution.
The nullity of the arbitration clause renders legitimate the initiative of the public administration to activate the power of self-protection through the issue of an executive assessment notice, as well as the opposition action brought before the ordinary court.
The executive assessment notice, not being a jurisdictional measure but an act issued directly by the administration or its concessionaire, does not of itself require the devolution to arbitrators of the merits of the challenge.