By: Alfonso Álvarez López
On October 16, 2025, an amendment to the Amparo Law promoted by the President of Mexico, Claudia Sheinbaum Pardo, was published in the Official Gazette of the Federation (Diario Oficial de la Federación). This amendment introduces various changes to the regulations on the matter, each of which contains elements that could be the subject of a specific analysis. However, this article will focus on four issues that, in the author's opinion, are the most relevant: a) legitimate interest; b) the limitation on the suspension of the contested act; c) the prohibition on the suspension of the contested act in cases of informal pretrial detention; and d) the retroactivity of the Amparo Law.
Firstly, a definition of legitimate interest is incorporated to the law, according to which the contested act must “cause the petitioner actual and differentiated legal harm, whether individual or collective,” and the granting of protection must generate a “true benefit and not merely a hypothetical or contingent one.” It should be kept in mind that, prior to the amendment, Article 5 of the law only mentioned a legitimate interest resulting from a “legal impact,” opening the scope to countless cases in which the petitioner's legal sphere is harmed, as opposed to what is now called “legal injury.” The inclusion of the term “legal injury” in the law creates ambiguity and a lack of procedural certainty, as there is no legal or doctrinal definition precising it.
It should be kept in mind that the legitimate interest serves as an intermediate legitimation in-between legal interest and simple interest, granting the petitioner protection against acts that affect its legal sphere without necessarily affecting a subjective right; however, this change causes this intermediate point to move closer to the legal interest, moving away from its “intermediate” origin. The term “legal impact” is broader and its elimination limits the scope of legitimate interest.
Secondly, regarding the limitations on the suspension of the contested act, now contained mainly in Articles 128 and 129 of the law, the amendment incorporates new sections and modifies the last paragraph of Article 128, restricting the scope of this legal concept. In the previous text, the requirements for ordering the suspension consisted essentially of: i) that it be requested by the petitioner, and ii) that it do not affect the social interest or contravene public order provisions. There was also a limitation in terms of economic competition, according to which the general rules, acts, or omissions of the Federal Telecommunications Institute (Instituto Federal de Telecomunicaciones) and the Federal Economic Competition Commission (Comisión Federal de Competencia Económica) were not subject to suspension.
With the amendment, new requirements for granting the suspension are added, which increase the burden of proof on the petitioner. It must be now demonstrated: (i) the existence of the contested act or its imminent occurrence; (ii) that the suspension will generate a direct and differentiated benefit for the petitioner (although this requirement is satisfied on a prima facie basis), which implies a unilateral and subjective assessment by the judge; (iii) the need to weigh the effects of the suspension against the public interest; (iv) and the likelihood of success, without this implying a prejudgment on the merits.
It can be argued that these requirements restrict citizens' access to suspension orders, that in a more or less immediate way, halt acts of authority that could infringe their rights, and which introduce obstacles to the effective protection of those rights. Furthermore, the wording rises broad and poorly defined criteria on how to satisfy these requirements, allowing the judicial authority to discretionally interpret them, which could easily restrict objectivity and facilitate the application of “tailor-made” criteria.
Reinforcing this idea, requirements (ii) and (iii) considered together, allow for a restrictive interpretation by the judge, which could affect collective rights. The foregoing since the wording of the requirements gives greater weight to social interest than to the specific impact on the petitioner or a specific group, thus allowing for the possibility of establishing a principle of relativity in the effects of the suspension with respect to the petitioner.
As for the limitation on economic competition, its scope is broadened to cover all the cases provided for in paragraphs fifteen and seventeen of Article 28 of the Constitution. Thus, this limitation now includes all the powers granted by the Constitution to the authorities responsible for ensuring free competition and market access, creating a scenario of possible defenselessness against the immediate consequences of the actions taken by the authorities in this area.
Thirdly, in the author's opinion, the most relevant and alarming modification to the Amparo Law in this amendment is the prohibition on judges to grant a suspension to the pretrial detention (“prisión preventiva oficiosa”) and to order the release of the accused. The addition of the sentence: “In such cases, the suspension may not be granted with effects other than those expressly provided for in this section” at the end of the first section of Article 166 of the Amparo Law, definitively prevents the judge from ordering the suspension of detention in cases of pretrial detention.
This provision not only constitutes a regulatory setback and a contradiction to the principles of pro-persona and presumption of innocence, but it is also unconventional, as it contravenes the provisions of Articles 7.1, 7.3, 7.5, 8.2, and 24 of the American Convention on Human Rights, relating to personal liberty and judicial guarantees. It also deliberately ignores the jurisdiction and binding force of the Inter-American Court of Human Rights (“IACHR”) by failing to comply with the judgment handed down in the case of García Rodríguez et al. v. Mexico (January 25, 2023), in which the Mexican State was ordered to bring its domestic legal system into line with the American Convention on Human Rights with regard to pretrial detention, as it was found to be incompatible with the Convention.
Currently, the authorities can, in full exercise of their powers, place a person in preventive detention solely on the basis of a complaint filed for one of the crimes listed in the catalog. 1 With the amendment, citizens are deprived of the only means of defense that in certain cases could allow them to remain free during trail. This opens the door to abuses of authority, allowing individuals to be arbitrarily deprived of their liberty without being able to be released until the criminal proceedings against them are resolved in their favor.
As mentioned above, this simple sentence definitively curtails the possibility that citizens can remain free during proceedings brought against them when they are placed in pretrial detention. Just like that, the criteria of the IACHR, as well as the principles of presumption of innocence and pro-persona, are dismissed.
Finally, the last element to be addressed in this work is the retroactivity of the amendment. This matter has been one of the most controversial during discussions in the Chambers of Congress (Cámaras del Congreso de la Unión), as some legislators argued that the wording of the third transitional Article of the amendment contravenes the provisions of Article 14 of the Constitution, which states: “No law shall be given retroactive effect to the detriment of any person.”
This transitional Article establishes the following: as this is a procedural law, proceedings that have already been concluded and have generated acquired rights will be governed by the law in force at the start of the process; however, future procedural actions will be subject to the provisions of the reform.
In other words, and as an example, if an amparo petition was filed before the amendment came into force and the suspension of the contested act has already been granted, it cannot be revoked, as the granting of the measure constitutes an acquired right. On the other hand, if the petition was filed before the amendment but the suspension had not yet been resolved, then the decision on that measure must comply with the new legal text resulting from the amendment.
However, a controversy arises. What happens in cases where an appeal is filed after the closing of a procedural stage? In the event that the petitioner has challenged an act of authority and the claim has been admitted in accordance with the law in force at the time of filing, but that, when an appeal is lodged, the court applies the new Amparo Law and determines that said act is no longer challengeable, thereby denying a favorable ruling, the petitioner procedural rights are affected.
Although the decision does not affect any acquired rights, since the claim is not being dismissed, the new law is being used affecting directly the procedural situation of the complainant, as well as the right to an effective remedy. The retroactive application of the law in proceedings already initiated causes prejudice to the petitioner, by changing the rules under which the right of defense was exercised creates legal uncertainty.
The wording of the transitional Article is misleading, as it appears to be harmless, when in fact it allows for the immediate application of the rule with unfavorable effects on proceedings already underway. It classifies the Amparo Law solely as a procedural law, when in fact it is both procedural and substantive, thus rendering the retroactive application of said law unconstitutional as it contravenes the provisions of Article 14 of the Constitution.
In conclusion, this amendment negatively impacts one of the most important means of defense available to the Mexican citizens, by increasing the initial burden of proof on the petitioner and establishing unjustified limits to the application of the most effective tool for curbing abusive or erroneous acts by the authorities: the suspension of the contested act. It is an amendment that even goes against the constitutional block, as it contravenes the American Convention on Human Rights.
This new text restricts and undermines the ability of Mexican citizens to defend themselves against the exercise of power and, ultimately, grants greater discretion to the judge and reduces the checks and balances on authority.
1 Provided for in Article 19, paragraph two, of the Political Constitution of the United Mexican States
