2027 Mexican legislative election

Political background

In the 2024 election, Sigamos Haciendo Historia, a coalition that included the National Regeneration Movement (Morena), the Ecologist Green Party of Mexico (PVEM), and the Labor Party (PT), won a majority of seats in Congress. The coalition obtained approximately 73% of the seats in the Chamber of Deputies, winning 256 of the 300 single-member districts and 108 seats through proportional representation, thereby achieving a supermajority in the lower house.^[1] In the Senate, the coalition initially fell three seats short of a supermajority; however, subsequent defections allowed it to reach that threshold.^[2] This marked the first time since the LIII Legislature that a governing party or coalition held a supermajority in both chambers of Congress.^[3]

The same election left the opposition substantially weakened. Fuerza y Corazón por México, the coalition of the National Action Party (PAN), the Institutional Revolutionary Party (PRI), and the Party of the Democratic Revolution (PRD) that had backed presidential candidate Xóchitl Gálvez, won less than a third of the presidential vote.^[4][5] The PRD, founded in 1989 and long the principal party of the Mexican left until the rise of Morena, lost its national registration after taking 1.86% in the presidential race, below the 3% threshold required to retain it, ending 35 years as a national party.^[5][6] The remaining opposition then fragmented further: in October 2025 the PAN's national leader, Jorge Romero, announced that the party would contest the 2027 election on its own, ending the electoral alliance with the PRI that the two had maintained since 2021.^[7] The PRI, led by Alejandro Moreno, pressed for a united opposition front, but the PAN and Citizens' Movement (MC), which had run alone in 2024, rejected the proposal, leaving the three parties set to compete separately against the governing coalition.^[8]

Following the inauguration of the LXVI Legislature, the ruling coalition used its supermajority to advance a package of constitutional amendments known as "Plan C", originally proposed by former president Andrés Manuel López Obrador and which President Claudia Sheinbaum campaigned on passing during the 2024 presidential election.^[9][10][11] The coalition frequently employed expedited or "fast-track" legislative procedures, limiting extended committee deliberation and accelerating the approval process.^[11] The coalition's control of more than two-thirds of each chamber also left the opposition unable to initiate constitutional challenges, as an Action of Unconstitutionality requires the support of at least 33% of the members of a legislative chamber to be filed.^[12][13] As a result, the coalition was able to approve controversial constitutional reforms along party-line votes, including the 2024 judicial reform, the transfer of the National Guard to military control, the adoption of the constitutional supremacy clause, and the dissolution of several autonomous constitutional bodies.^[11] However, by late 2025, the coalition's internal unity also began to weaken. In December 2025, the PT broke ranks for the first time, abstaining on Sheinbaum's revision of Mexico's import and export tariff law.^[14] In early 2026, when Sheinbaum pursued an electoral reform that was widely seen as disadvantageous for smaller parties, the PT and PVEM mostly voted against it, marking the first time Morena's coalition partners voted against one of Sheinbaum's constitutional initiatives.^[15][16][17]

Summary

Creation of new parties

In January 2025, the registration period opened for political organizations seeking recognition as national political parties, during which 89 organizations formally registered their intent to do so.^[20] To obtain registration, an organization had to affiliate at least 0.26% of the national electoral roll—256,030 voters—by 28 February 2026.^[21] It also had to hold either 20 state assemblies attended by at least 3,000 people each, or 200 district assemblies of at least 300 people each, by 15 February 2026,^[22] in accordance with electoral law.^[20][23]

Of the 89 organizations, 31 withdrew, and five formally applied for registration in February 2026; four of them met the affiliation and assembly requirements.^[24] On 24 June 2026, the INE's Commission on Prerogatives and Political Parties recommended that the General Council grant national-party registration to these four.^[25] The following day, the General Council approved two of them—Building Societies of Peace (PAZ) and We Are Mexico (Somos MX)—and rejected the applications of México Tiene Vida and Que Siga la Democracia.^[26] PAZ was a successor to the Social Encounter Party and the Solidarity Encounter Party, while Somos MX grew out of the Marea Rosa (lit. 'pink tide'), a citizens' movement that arose in 2022 in defence of the INE's autonomy against an electoral reform proposed by President Andrés Manuel López Obrador and that backed Xóchitl Gálvez in the 2024 presidential election.^[26][27][28]

The General Council denied registration to México Tiene Vida by six votes to five and to Que Siga la Democracia by seven votes to four.^[29] It found that ministers of religion had participated in at least 58 of México Tiene Vida's assemblies, conduct prohibited by electoral law, and cited financial irregularities including an undeclared corporate donation and an attempted bribe of an electoral official.^[26][30][31] Que Siga la Democracia was rejected for 92 affiliation records that contained altered photographs and falsified voter credentials, along with unreported expenditures and payments to citizens to attend its assemblies.^[32][33] A last-minute report by the Financial Intelligence Unit (UIF) also alleged that resources had been channelled through shell companies to the organization's president, Édgar Garza, an allegation he denied.^[31] Several INE councillors criticised the UIF report as irregular and untimely.^[34]