Reforms to the Amparo Law that took place during 2013 made it possible to bring a constitutional challenge against private entities or individuals that perform activities equivalent to those performed by government authorities. Prior to that reform, amparo was only available as a remedy against acts performed by government authorities. This new version of the Amparo Law was used to sue arbitrators as if they were authorities (in a fashion similar to state judges) and, at the same time, challenge awards on the basis that the award violated the fundamental or human rights of the losing party.
Fortunately, from 2015 onwards, there were several judicial resolutions that confirmed the private nature of commercial arbitration and that arbitrators are not to be regarded as authorities of the state for the purposes of the Amparo law. In a relatively recent judicial precedent (jurisprudence thesis), the federal Mexican judiciary confirmed that arbitrators cannot be regarded as “responsible authorities” for the purposes of the Amparo Law. The core reasoning in this precedent is: “although private arbitrators are empowered to resolve legal disputes that the parties submit to them, as it stems from an agreement made between individuals, the role of arbitrators is private and all activities carried out by them in order to resolve the dispute in question have the same character; that is, they are not state officials nor have their own or delegated jurisdiction, since their powers derive not from a general rule, but from the will of the parties expressed in the [arbitration] agreement that the law recognizes, and as one who appoints arbitrators and determines the limits of their office does not act in the public interest, that is, as an organ of the state, but in his own private interest, of course the functions of such arbitrators are not public but private, which means they lack imperium, so that the same arbitrators cannot be conceptualized as state authorities and their actions are not equivalent to those of an official authority.”
This precedent is important to prevent attacks on arbitration using the amparo as a means to delay and obstruct the arbitrators’ appointment or the continuance of arbitral proceedings on the argument that arbitrators should subject to the possibility of an amparo action and their acts (procedural orders, interim decision, awards, etc.) subject to scrutiny through this form of constitutional control. In summary, this precedent confirms the principle of no judicial intervention in arbitration and the longstanding position of Mexican law and the judiciary that the only remedies against the acts of the arbitrators are those established in the arbitration law, which, in Mexico, are simply those of the UNCITRAL Model Law.
 Amparo refers to an extraordinary judicial remedy intended to allow a person to question whether or not a certain action or law conforms with the rights protected under the Mexican Constitution.
 Article 5 of the current Amparo Law reads: “Are parties to the amparo proceeding: […] II. The responsible authority, being held as such, despite its formal nature, the one that pronounces, orders, enforces or attempts to enforce the act that creates, modifies, or terminates legal situations in a unilateral and obligatory manner; or fails to perform the act, that, if performed, would create, modify or terminate such legal situations. For the purpose of this Law, private parties will be held as a responsible authority when they perform acts equivalent to those of an authority, that affect rights in terms of this section, and whose functions are determined by a general law […]”
 Thesis I.8o.C.23 C (10a.) of the Eighth Collegiate Tribunal in Civil Matters of the First Circuit, published in the weekly Gazette of the Federal Judiciary on 15 May 2015 under the title Private arbitrators do not have the character of responsible authorities in the amparo proceeding.