The Neighborhoods That Could Flip on November 29: Spain's Electoral Map, Section by Section

We applied our forecast to each of Spain's 36,459 census sections. Nearly one in seven voters lives in a section whose favorite is no longer the party that won there in 2023, almost always a shift from the Socialists (PSOE) to the conservative People's Party (PP), and the hard-right Vox starts as the favorite in more than 1,200 sections, up from 65 three years ago. Here are the areas on the edge and the provinces where a local poll would move the most seats.

21 October 2026 · Miguel · Leer en español

On November 29, Spaniards will vote at about 60,000 polling stations, but a polling station is not a place: residents of the same census section are assigned to its stations by the alphabetical order of their surnames. The unit with geography, and the one that is useful for tracking the vote, is the section: a neighborhood or village of 500 to 2,500 voters. Spain had 36,459 of them with votes in 2023.

In “Swing Spain” we counted how many have changed hands since 2008. Here we look ahead: we ran our forecast’s simulations through every section to see which party starts as the favorite in each one, and how confidently.

Nearly one in seven voters lives in a section with a new favorite

• For 13.3% of voters, the favorite in their section for November 29 is not the party that won there in 2023. By far the most common change is from the PSOE to the PP: 8% of all voters.
• Taking into account the probability of each outcome, not just the favorite, the average share of voters in sections that would change hands is 23%.
• 18.2% live in sections on the edge, where no party finishes first in more than 60% of simulations.
• The PP was ahead of the PSOE in sections home to 49.6% of voters in 2023; under the forecast, it would be ahead in sections home to 57.5%.

Vox won 65 sections in 2023; it now starts as the favorite in 1,216. That is not enough to win any province, but it is enough to come first in specific neighborhoods and towns in Murcia (200 sections), Cádiz (103), Almería (89), Las Palmas (85), Málaga (78), Toledo (68), Valencia (62) and Madrid (56).

Where the edge is

% of each district's voters. Expected change: average probability that the leading party in their section differs from 2023. Toss-up: sections whose favorite comes first in under 60% of simulations. Favorite differs: the party that finishes first most often is not the 2023 winner.

Las Palmas, Guadalajara, the Balearic Islands, Valencia and Cádiz top the list with sections that would shift from the PSOE to the PP. In Toledo, Almería, Murcia and Ceuta, the most common change is from the PP to Vox. In Álava and Biscay, in the Basque Country, the contest is between the PSOE and the Basque nationalists, EH Bildu and the PNV.

Four cities, section by section

Colmenar Viejo: one section that sums it all up

In the province of Madrid, the section with the most flips and the narrowest 2023 margin among those with more than 600 voters is in Colmenar Viejo, north of the capital: section 2804501004, with 1,496 voters. Since 2008, the PP and the PSOE have traded the lead there four times, and in 2023 the PP won by 0.4 points. It is younger (average age 40.8), with lower income (€13,240 per person) and fewer college graduates (25%) than the average of the town’s sections (€16,845 and 37%): exactly the profile of swing Spain.

For November 29, the PP starts as the favorite there, but only in 62% of simulations; the PSOE comes first in 32%. Across the town, the PP is the favorite in every section, but in four of them, home to 13% of voters, it falls short of 60% of simulations. The most uncertain is a different one, section 2804501003, which the PSOE won in 2023: the PP comes first in 36% of simulations, Vox in 34% and the PSOE in 30%.

Beyond the PP and the PSOE

In Catalonia and the Basque Country, the question that decides many sections is not whether the PP or the PSOE is ahead, but whether nationalist parties together outpoll everyone else.

• Catalonia. Nationalist parties went from leading in 2% of sections in 2008 to 47% in November 2019, and fell back to 18% in 2023. 30.9% of voters live in sections that have switched sides twice or more on this axis.
• Basque Country. A similar back-and-forth: from 11% in 2008 to 47% in 2011 and in November 2019, and 39% in 2023. Swing sections are home to 28.1% of voters.
• Navarre. Adding the regional UPN to the PP (they have run together or separately depending on the election), 42.3% of voters live in right-wing strongholds and 37.9% in swing sections.
• Asturias. Adding the regional Foro party to the PP, 79.3% of voters live in swing sections: the region that changes hands the most in the whole series.

If we had to poll: where to look

In our simulations, the PP and Vox together win an absolute majority 99% of the time; a three-fifths majority (210 seats) only 23% of the time. What remains open depends on the last seats in each province and, above all, on uncertainty that is not national: in each district, the national vote explains only 10% to 35% of how many seats the PP and Vox win. The rest depends on what happens in the province itself, and only a poll conducted there could resolve it.

Local uncertainty: standard deviation of PP and Vox seats in the district left after accounting for the national vote in each simulation, the part that only local information can resolve. In brackets, the probability that the party currently holding the last seat keeps it.

The big provinces concentrate more seats in play, but there is another way to look at it: where the last seat is a toss-up and most voters live in sections that change hands. There, a few thousand votes decide a member of Congress: Santa Cruz de Tenerife, the Balearic Islands, Asturias, Cantabria, Valladolid, Ciudad Real and Huesca. A survey of 8,000 interviews well spread between the four big ones (Madrid, Barcelona, Valencia and Málaga) and those six or seven smaller ones would resolve much of what is still open.

What this analysis does not say

• It assumes each province moves as a block, plus a margin of its own for each section. That margin is calibrated on how far each section strayed from its province between 2019 and 2023. It knows nothing about candidates, local campaigns or population changes since 2023.
• New parties have no starting point by section. Se Acabó La Fiesta and Adelante Andalucía did not run in 2023 and are left out of this calculation; Frente Amplio and Podemos are counted together, as they ran within Sumar in 2023.
• Spaniards abroad are not included. This is the vote of each section’s residents; the overseas vote is counted separately in each province.
• A favorite section is not a seat. Seats are allocated by province; sections show where the vote is moving, not how many members of Congress each party gets.

How we calculated it

• Starting vote. Interior Ministry polling-station results for 2023, added up by section, as a percentage of valid votes including blank ballots.
• Forecast. 2,000 of the 50,000 simulations of the altnalysis model of October 20. In each one, the change in each party’s vote in the province (on a logistic scale) is applied to all of its sections, plus a section-specific error with variance a + b / votes in the section, fitted for the PP, the PSOE, Vox and the left on the changes between November 2019 and 2023.
• Categories. Safe favorite: first in 95% of simulations or more; leaning, between 60% and 95%; on the edge (toss-up), below 60%.
• Regional axes and swing sections. Sections stable across the seven general elections since 2008, as in “Swing Spain.”
• Local uncertainty. Regression, simulation by simulation, of PP and Vox seats in each province on the national vote of the PP, PSOE, Vox and Frente Amplio.
• Code. pronostico_secciones.py, secciones_regiones.py, focalizacion.py and articulo_secciones26.py, in the altnalysis repository.