The challenge to an arbitral award for violation of rules of law relating to the merits of the dispute, governed by Article 829 paragraph 3 of the Code of Civil Procedure, is permitted only if expressly provided for by the parties or by law, as well as in case of contrariety to public policy, understood as the body of fundamental and mandatory rules of the legal system that express essential values, excluding mere imperative norms.
The proceedings for challenging an arbitral award do not constitute appeal proceedings, having as their sole object the verification of the legitimacy of the decision rendered by the arbitrators and not the re-examination of questions of merit, so that the factual findings made by the arbitrators are not open to criticism, except in the case where the reasoning of the award is completely absent or absolutely deficient.
The proceedings for nullity of an arbitral award are subject to limited grounds of review and may be brought only within the limits established by Article 829 of the Code of Civil Procedure, the rule of specificity in the formulation of grounds applying, consistent with the rescissory nature of the proceedings and with the necessity of enabling the judge and the opposing party to verify the correspondence of the challenges with those that may be formulated under the applicable legislation.