As of , Morena, President Claudia Sheinbaum's left-wing party, has 52.4% of the decided vote for the Chamber of Deputies, 37.0 points ahead of the conservative PAN (National Action Party) (15.4%), in the Sondagio average of the latest poll from 6 pollsters. Together, Morena and its governing allies, the Greens (PVEM) and the Labour Party (PT), reach 60.0%; the three opposition parties, PAN, PRI and Citizens' Movement (MC), total 37.1%.
6pollsters in the average
37.0 ptsMorena–PAN gap
22.9 ptsgoverning bloc's lead
22%undecided or none (excluded)
Latest pollDe las Heras Demotecnia · · 1,000 voters
The midterm ("elección intermedia") renews all 500 seats of the Chamber of Deputies, the lower house of Congress, halfway through President Sheinbaum's six-year term (2024–2030). The Senate is not up; it is next elected with the president in 2030.
The system is mixed: 300 deputies are elected first-past-the-post, one per district, and 200 by proportional representation from party lists in five regional constituencies. No party may hold more than 300 seats in total, or seats exceeding its vote share by more than 8 points.
Morena (founded by former president Andrés Manuel López Obrador) has governed since 2018, allied with the Labour Party (PT) and the Green Party (PVEM). In 2024 that alliance won a two-thirds majority in the Chamber, the share needed there to pass constitutional amendments.
The opposition: the centre-right PAN, the PRI (which ruled Mexico for most of the 20th century) and the centrist Citizens' Movement (MC), which stayed out of the PAN–PRI alliances of 2021 and 2024. The PAN has said it will not renew a national alliance with the PRI for 2027.
Chamber of Deputies 2027 poll average
% of decided vote · 75 days
Party
Average
Range across pollsters
Polls
Morena (National Regeneration Movement)
52.4%
41.4 – 66.7
6
PAN (National Action Party)
15.4%
11.6 – 20.4
6
MC (Citizens' Movement)
11.0%
7.2 – 15.0
6
PRI (Institutional Revolutionary Party)
10.7%
8.7 – 12.9
6
PVEM (Green Party)
5.1%
2.9 – 6.9
6
PT (Labour Party)
2.5%
1.4 – 3.3
6
SOMOS
1.5%
1.1 – 2.8
6
PAZ
0.6%
0.0 – 1.3
5
OthersOthers
1.6%
0.6 – 3.1
3
Logos: Wikimedia Commons (public domain).
National polls for the Chamber are still scarce, so the average takes each pollster's latest poll published in the 75 days before the newest one (not the 21 days used on other Sondagio pages). "Polls" = how many of the 6 pollsters ask about that party. SOMOS and PAZ are new parties, listed as the source records them.
Government vs opposition: the vote by bloc
Sum of averages · no seat projection
MorenaPVEMPT
60.0%of the decided voteGoverning parties (Morena, PVEM, PT)
PANPRIMC
37.1%of the decided voteOpposition (PAN, PRI, MC)
Governing parties from the left, opposition from the right, others in the middle · line = 50% of the vote
Why no seat projection? Who wins each of the 300 districts depends on which parties run joint candidates, and the 2027 coalitions have not yet been registered with the INE. We will publish a seat projection once they are, in early 2027. Until then the blocs are simply each party's vote added up; they do not assume the parties will run together.
2026 electoral reform: on March 11, 2026 the Chamber of Deputies rejected President Sheinbaum's constitutional reform (it fell short of the two-thirds majority). A narrower constitutional "Plan B", mainly cutting state-congress budgets, the number of local councillors and electoral officials' pay, was approved by Congress and a majority of state legislatures in April 2026 and, according to published reports, does not change the make-up of the Chamber (300 + 200). The detailed rules for 2027 may still be refined; we will update this note when the INE publishes the electoral calendar.
How the polls have moved since 2025
Weekly average
Each dot is a published poll. The line is the Sondagio average (each pollster's latest poll in the previous 75 days), one point per week.
Reference map: 2024 presidential election by state
Official 2024 result · not a 2027 estimate
Sheinbaum (Morena and allies): 31 states Gálvez (PAN-PRI-PRD): 1 state Máynez (MC): 0 states
The map shows who carried each of Mexico's 32 states in the 2024 presidential election, for reference. There are no state-level polls for the 2027 Chamber election, so we do not estimate results by state.
Parties: % of decided vote (rescaled). *Undecided: % answering "none" or "don't know / no answer" in the original poll.
How we calculate
Decided vote: from each poll we remove "none" and "don't know / no answer" and rescale the rest to 100. That is why the figures are higher than the ones each pollster publishes, which in Mexico usually include a large undecided share.
Average: each pollster's latest poll with fieldwork ending in the 75 days before the newest poll; simple mean per party. We use 75 days because national polls for the Chamber are sparse.
Blocs: the sum of the averages of Morena, PVEM and PT (the parties that govern together) and of PAN, PRI and MC (the opposition). This is vote arithmetic, not a forecast of coalitions or seats.
Data: every published poll, compiled on Wikipedia (CC BY-SA 4.0). Each row links to the original publication.
Map: official 2024 presidential result by state (INE district counts). Boundaries: geoBoundaries (CC BY 4.0).
Poll ban (veda electoral, LGIPE art. 213): no polls may be published from three days before the election until polling stations close in the westernmost time zone. From June 3, 2027 until 8 p.m. Mexico City time on June 6, the figures on this page are frozen.
Independence: Sondagio's founder has no ties to any candidate or campaign. The averages are calculated by formula from every published poll; no figures are adjusted by hand.
Morena (National Regeneration Movement)
PAN (National Action Party)
MC (Citizens' Movement)
PRI (Institutional Revolutionary Party)
PVEM (Green Party)
PT (Labour Party)
SOMOS
PAZ