INE sets rules for total, partial, and flexible coalitions for 2027

The General Council of the National Electoral Institute approved the guidelines that national political parties seeking to form coalitions for the election of deputies by the principle of relative majority, in its various modalities, must observe for the 2026-2027 Federal Electoral Process. The agreement, identified by the key INE/CG564/2026, was published in the Official Gazette of the Federation on Monday, October 19, 2026, and sets the deadline for submitting registration requests for coalition agreements and participation accords as January 4, 2027.

The instrument was approved in general by unanimous vote during the ordinary session on September 24, 2026, with the support of the eleven electoral councilors, led by the presiding councilor Guadalupe Taddei Zavala. Specifically, the last paragraph of page 33 of the project and the applicable part of the guidelines were approved by ten votes in favor and one against, from councilor Arturo Castillo Loza. The agreement is based on articles 85 to 92 of the General Law of Political Parties and 275 to 279 of the Institute’s Election Regulations.

Three modalities with nomination thresholds

The first resolutive point of the agreement details the permitted modalities and the minimum number of formulas each requires:

• Total coalition: nomination of the 300 candidacy formulas for relative majority deputies.
• Partial coalition: at least 150 candidacy formulas for relative majority deputies.
• Flexible coalition: at least 75 candidacy formulas for relative majority deputies.

The three modalities must adhere to the requirements, formalities, and procedure of the annexed guidelines, which form an integral part of the agreement. The document also specifies that coalitions must observe the same gender parity rules as parties, even in the case of partial or flexible coalitions.

Uniformity: no dynamic combinations

The General Council maintained that coalitions must comply with the principle of uniformity, understood as the coincidence of the member parties and joint action in the registration of candidacies. Therefore, it resolved that “it will not be permissible to establish different combinations of the member parties of the same coalition to support specific candidacies for relative majority deputies.”

This criterion draws upon Jurisprudence 2/2019 of the Superior Chamber of the Electoral Tribunal of the Federal Judiciary, derived from file SUP-RAP-718/2017, which obliges coalesced parties to nominate jointly and as a unit all candidacies included in their agreement. The agreement also recalls that no party may be part of more than one coalition in the same federal electoral process.

Deadlines and roadmap toward the June 2027 election day

The electoral calendar is linked to the registration date of the agreements:

• January 4, 2027: deadline to submit registration requests for coalition agreements and participation agreements before the Presidency of the General Council or, in its absence, before the Executive Secretariat.
• January 4, 2027: start of federal pre-campaigns, in accordance with agreement INE/CG563/2026.
• February 12, 2027: conclusion of pre-campaigns, according to resolution INE/CG478/2026.
• June 6, 2027: election day, the first Sunday of June.

The Institute specified that agreements may be modified from their approval until one day before the start of the candidacy registration period, provided that the modification does not imply changing the registered modality. Likewise, it recalled that the newly registered parties SOMOS and PAZ may not form coalitions, due to the prohibition in Article 85, numeral 4, of the party law.

Effective affiliation and consultations

The agreement instructs the Prerogatives and Political Parties Commission to submit to the General Council, no later than November 2026, the mechanism for applying the formula for the allocation of seats by proportional representation, which must include the regulation of the “effective affiliation” criterion. It also empowers that commission and the Audit Commission to handle consultations from the parties, with support from the Technical Audit Unit regarding expenditure.

The relevance of the instructional is twofold: it organizes the parties’ alliance strategy for the only federal election of 2027—the renewal of the Chamber of Deputies—and connects it with the 19,609 positions that will be elected concurrently across the 32 federal entities, in single polling stations and with multiple ballots.

Source: Official Gazette of the Federation, October 19, 2026, Section I, page 205 (official reference: INE/CG564/2026).