Article 54 Political Constitution of the United Mexican States
Third Title · Chapter II. On the Legislative Power · Section I. On the Election and Installation of the Congress
Current text · last reform published in the Official Gazette of the Federation (DOF) on 2 June 2026
The election of the 200 deputies according to the principle of proportional representation and the system of assignment by regional lists shall be subject to the following bases and to what the law provides:
I.A political party, to obtain the registration of its regional lists, must accredit that it participates with candidates for deputies by relative majority in at least two hundred single-member districts;
II.Every political party that reaches at least three percent of the total valid vote cast for the regional lists of the plurinominal circumscriptions shall have the right to be attributed deputies according to the principle of proportional representation;
III.The political party that complies with the two preceding bases, independently and additionally to the certificates of relative majority that its candidates have obtained, shall be assigned by the principle of proportional representation, in accordance with its national vote cast, the number of deputies of its regional list that corresponds to it in each plurinominal circumscription. In the assignment the order that the candidates had in the corresponding lists shall be followed.
IV.No political party may count with more than 300 deputies by both principles.
V.In no case may a political party count with a number of deputies by both principles that represent a percentage of the total of the Chamber that exceeds by eight points its percentage of national vote cast. This base shall not be applied to the political party that, by its triumphs in single-member districts, obtains a percentage of seats of the total of the Chamber superior to the sum of the percentage of its national vote cast plus eight percent; and
VI.In the terms of what is established in sections III, IV and V above, the proportional representation deputations that remain after assigning those corresponding to the political party that is found in the cases of sections IV or V shall be awarded to the other political parties with right to it in each one of the plurinominal circumscriptions, in direct proportion with the respective effective national votes of these latter. The law shall develop the rules and formulas for these effects.