The evolution of legislative elections in Portugal is depicted in a study released today by Pordata, coinciding with the 50th anniversary of the first free elections on April 25, 1975, for the Constituent Assembly.
“The election with the highest participation rate was in 1979, although the 2024 elections saw the highest number of votes in absolute terms (6,473,789): both resulted in victories for the Democratic Alliance (AD), led by Sá Carneiro in 1979 and Luís Montenegro in 2024,” states the Pordata database, part of the Francisco Manuel dos Santos Foundation.
In the 17 legislative elections held in Portugal, more than half of the electorate consistently voted, except in the 2019 elections, which resulted in a victory for António Costa’s PS, where “the official abstention rate was 51.4%,” according to Pordata.
However, Pordata notes that since the 2009 elections, the participation rate has not exceeded 60%.
Across the 17 legislative elections—excluding those for the Constituent Assembly—there were only three instances where the PS and the parties comprising the AD (PSD and CDS-PP) did not jointly secure more than two-thirds of all valid votes: in 1980 (49.9%), 1985 (52.1%), and 2024 (59.4%).
In two of these elections, there was a significant rise in parties beyond the PS and PSD: in 1985, the Democratic Renewal Party (PRD), led by António Ramalho Eanes, secured 18.4%, jumping from zero to 45 deputies, marking the largest growth of a party in democracy.
Similarly, in 2024, Chega nearly matched PRD’s growth in 1985: “with 18.1% of the votes, the party increased from 12 to 50 deputies compared to the 2022 elections,” the study reports.
Pordata emphasizes that, in a democratic setting, the party receiving the most votes in a legislative election was the PSD in 1991, when Cavaco Silva was re-elected with an absolute majority and garnered 2.9 million votes.
However, it was the PS that elected the most deputies in an election in 2015, with 121 deputies. The PS also saw the steepest decline in the number of deputies from one election to another, losing 42 seats in the 2024 elections, decreasing from 120 to 78 mandates.
Regarding gender parity, the study mentions that since 2015, “women have comprised at least 30% of the deputies elected to the Assembly of the Republic,” a significant contrast compared to the first legislative elections on April 25, 1976, which elected the fewest women in democracy: only 15 female deputies, accounting for 5.7% of the total.
The Assembly with the highest number of women was in 2019, “where approximately four in ten deputies were women (38.7%),” the study notes.
Analyzing the Portuguese electoral system, Pordata highlights that the four largest electoral constituencies—Lisbon, Porto, Braga, and Setúbal—elect more than half of the deputies (126 out of 230). In the last elections, PSD, PS, and Chega secured more than 90% of parliamentary seats despite having 78% of valid votes due to the d’Hondt method.
“The AD, together with the PSD/CDS-PP coalition from the Madeira constituency, elected 35% of the total deputies (80/230) with 30% of the valid votes, PS secured 34% of the AR mandates (78/230) with 29% of the votes, and Chega elected 22% of the deputies (50/230) with 19% of the valid votes,” the report says.
