Portugal Parliamentary Elections

Updated May 18, 2025
100%
AD most seats
0%
PS most seats
0%
Right majority
0%
Left majority

Polling trends

Smoothed polling averages based on 13056 data points. Lines show estimated vote share over time with uncertainty bands.

Coalition seat distributions

Showing 9000 simulation outcomes

Each dot represents one simulation outcome. Black lines show median seat counts for each coalition.

Individual party projections

Based on 9,000 Monte Carlo simulations. Dots show mean projections, bands show 50% and 80% credibility intervals.

District Analysis

District Map

Seats in Play (7 districts)

Districts where seat allocation is uncertain - small changes in vote share could flip seats between parties.

Lisboa

ENSC: 3.04
Chega
+1 seat: 26%-1 seat: 30%
Partido Socialista
+1 seat: 43%-1 seat: 10%
Aliança Democrática
+1 seat: 24%-1 seat: 26%

Porto

ENSC: 2.17
Chega
+1 seat: 47%-1 seat: 7%
Iniciativa Liberal
-1 seat: 46%
Aliança Democrática
+1 seat: 27%-1 seat: 18%

Braga

ENSC: 1.37
Chega
+1 seat: 48%
Livre
+1 seat: 40%
Aliança Democrática
+1 seat: 27%

Aveiro

ENSC: 1.29
Aliança Democrática
-1 seat: 46%
Partido Socialista
+1 seat: 45%
Livre
+1 seat: 14%

Leiria

ENSC: 1.04
Partido Socialista
+1 seat: 46%
Chega
+1 seat: 34%
Iniciativa Liberal
+1 seat: 16%

Castelo Branco

ENSC: 1.00
Partido Socialista
-1 seat: 50%
Aliança Democrática
-1 seat: 50%

Guarda

ENSC: 0.99
Chega
+1 seat: 50%
Aliança Democrática
-1 seat: 50%

Likely Winners by District

8
Aliança Democrática
districts
4
Partido Socialista
districts
1
Chega
districts
20
Total districts
7
Seats in play
13
Stable allocation

ENSC (Effective Number of Seat Changes) measures seat allocation uncertainty. Districts with ENSC > 0.8 are classified as having "seats in play" where small vote share changes could flip seats between parties under the D'Hondt proportional system.

Left

Socialist Party
27.7%
Left Bloc
2.7%
Unitary Democratic Coalition
3.2%
LIVRE
4.7%
Majority chance0%

Right

Democratic Alliance
34.2%
Liberal Initiative
5.6%
Majority chance0%

Polling house effects

PollsterADPSCHILBECDULPAN
Aximage-0.04
AximageAD: -0.038 logit
AximagePS: -0.006 logit
AximageCH: 0.018 logit
+0.05
AximageIL: 0.051 logit
AximageBE: -0.008 logit
AximageCDU: -0.016 logit
+0.09
AximageL: 0.094 logit
+0.04
AximagePAN: 0.041 logit
CESOP-U.Católica
CESOP-U.CatólicaAD: 0.010 logit
CESOP-U.CatólicaPS: 0.006 logit
-0.03
CESOP-U.CatólicaCH: -0.025 logit
+0.18
CESOP-U.CatólicaIL: 0.175 logit
CESOP-U.CatólicaBE: -0.018 logit
CESOP-U.CatólicaCDU: 0.004 logit
+0.15
CESOP-U.CatólicaL: 0.152 logit
-0.14
CESOP-U.CatólicaPAN: -0.139 logit
Consulmark2+0.03
Consulmark2AD: 0.027 logit
-0.03
Consulmark2PS: -0.028 logit
Consulmark2CH: -0.010 logit
+0.22
Consulmark2IL: 0.220 logit
Consulmark2BE: 0.011 logit
-0.04
Consulmark2CDU: -0.039 logit
+0.22
Consulmark2L: 0.222 logit
-0.21
Consulmark2PAN: -0.213 logit
ICS/ISCTE/GFK Metris
ICS/ISCTE/GFK MetrisAD: 0.019 logit
+0.04
ICS/ISCTE/GFK MetrisPS: 0.038 logit
+0.04
ICS/ISCTE/GFK MetrisCH: 0.043 logit
-0.24
ICS/ISCTE/GFK MetrisIL: -0.239 logit
ICS/ISCTE/GFK MetrisBE: -0.016 logit
+0.06
ICS/ISCTE/GFK MetrisCDU: 0.064 logit
-0.39
ICS/ISCTE/GFK MetrisL: -0.390 logit
+0.04
ICS/ISCTE/GFK MetrisPAN: 0.037 logit
Intercampus-0.12
IntercampusAD: -0.116 logit
-0.08
IntercampusPS: -0.077 logit
IntercampusCH: -0.005 logit
+0.25
IntercampusIL: 0.246 logit
IntercampusBE: 0.017 logit
-0.06
IntercampusCDU: -0.057 logit
+0.24
IntercampusL: 0.237 logit
+0.27
IntercampusPAN: 0.265 logit
Metris
MetrisAD: 0.004 logit
MetrisPS: 0.017 logit
MetrisCH: 0.010 logit
MetrisIL: 0.016 logit
MetrisBE: 0.005 logit
MetrisCDU: 0.018 logit
-0.19
MetrisL: -0.191 logit
-0.04
MetrisPAN: -0.043 logit
Pitagorica
PitagoricaAD: 0.004 logit
PitagoricaPS: 0.010 logit
-0.03
PitagoricaCH: -0.026 logit
+0.19
PitagoricaIL: 0.191 logit
-0.04
PitagoricaBE: -0.039 logit
PitagoricaCDU: 0.009 logit
+0.20
PitagoricaL: 0.196 logit
-0.11
PitagoricaPAN: -0.108 logit

House effects show how each pollster systematically differs from the polling average in logit space. Red cells indicate the pollster tends to show higher support for that party, blue cells show lower support.

Values are logit deviations. Larger absolute values indicate stronger systematic bias. Hover over cells for exact values.

About this model

Data sources

Polling data from major Portuguese polling firms, weighted by reliability and recency. Historical election results and demographic data.

Methodology

Monte Carlo simulation accounting for polling uncertainty, district-level variations, and D'Hondt seat allocation system.

Updates

Model is updated as new polling data becomes available. Uncertainty decreases as election day approaches.