In every legal system there is a possibility to request that the courts review the validity of an arbitral award on listed grounds, which can never affect the arbitrators’ substantive decision. The analysis of the various systems of challenging an award reflects the importance of the choice of the arbitration seat. There is no legal remedy against the decision ending the challenge of an award, with the exception of an application for a declaration of fundamental rights ("recurso de amparo constitucional"). The Constitutional Court shows that arbitral awards cannot be directly subject to such application ("recurso de amparo"), just as the guarantees of article 24 of the Constitution cannot be transferred in their position as a fundamental right to the arbitration procedure.
The Spanish legal system does not permit the "exclusion clause" of the right to challenge an award in arbitral agreements, as occurs in most comparable legal systems. This fact does not in any way affect the soundness and effectiveness of the Spanish arbitration system.
Finally, the article analyzes the problem of the intervention of arbitrators in an arbitration at law when either party’s claim is based on the fact that the applicable law to substantively decide the matter is against the Constitution or European Union Law.