Small Constituencies Matter (II): Cantabria, La Rioja, Navarre, Murcia and the Other Provinces Where the Last Seat Is Decided

In La Rioja, the far-right Vox, the conservative People's Party (PP) and the Socialists (PSOE) are fighting over the fourth seat; in Navarre, four parties have a real chance at the last one; in Cantabria, the PSOE and the PP are fighting over the fifth, which in 2023 fell to Vox by 403 votes. We review eight provinces with our forecast for November 29 and their history since 2008: how many votes decided their last seat and who can take it now.

24 October 2026 · Miguel · Leer en español

In the first part we explained why the last seat in small provinces weighs so much: there are few seats, the real threshold to get in is high, and a few thousand votes move a member from one bloc to another. Here we go into the detail of eight constituencies: four with four or five seats (Cantabria, La Rioja, Navarre and Álava), three with two or three (Soria, Teruel and Huesca), and Murcia, which elects ten but has one of the tightest last seats in Spain.

Cantabria: the fifth seat, between the PSOE and the PP

In 2023 the PP got 42.1% and two seats, the PSOE 33.3% and two, and Vox 14.1% and one. That Vox seat was the last one, and it won it by 403 votes over the PP’s third: the narrowest margin of 2023 in all of Spain after Girona. It was not the first time Cantabria’s last seat was decided narrowly: in 2011 the PP won it by 1,802 votes over the PRC (the Cantabrian regionalists), and since 2008 it has changed party four times.

For November 29, the forecast gives the PP 38.8% (between 30% and 48% in 95% of simulations), the PSOE 27.7% and Vox 21.2%. Vox is almost certain to get at least one seat (it wins one in 99% of simulations). The doubt is the fifth: whether it goes to the PSOE, which would keep two, or to the PP, which would have three. The PSOE wins it in 51% of simulations and the PP in 39%, with a median difference of about 15,000 votes.

La Rioja: Vox against the threshold

La Rioja elects four members, and with four the effective threshold is around 15%. In 2023, with 9.8%, Vox was left out: the PP and the PSOE split two and two. Now the forecast gives it 16.7% (between 11.5% and 22.9%), right around that threshold.

The fourth seat is a three-way fight. Vox wins it in 48% of simulations, the PP (which would have three) in 30% and the PSOE (which would keep two) in 22%. Vox gets a member in 61% of simulations; the PSOE keeps one in 75%. It is the textbook case of how a couple of points around the threshold change an entire seat. La Rioja is also one of the most volatile provinces: its last seat has changed party five times in six elections, and in 2015 it was decided by 1,261 votes.

Navarre: four parties for one seat

Navarre elects five members and has the most fragmented map of the eight. In 2023 the PSOE won two, and EH Bildu (the Basque left), the PP and UPN (the Navarrese conservatives) one each. For November 29, UPN and the PP run in coalition, and the forecast gives them 29.6%; the PSOE, 23.5%; EH Bildu, 18.4%, with a very wide interval (between 8% and 37%); and Vox, 10.3%.

The last seat is open as nowhere else: the PSOE takes it in 35% of simulations, the PP in 27%, EH Bildu in 20% and Vox in 16%. The median difference is about 7,200 votes. Navarre has already decided its last seat by fewer than a thousand votes twice: in 2011 Geroa Bai (a Basque-nationalist and left-leaning coalition) won it by 729 votes, and in April 2019 the PSOE took it from EH Bildu by 511.

Murcia: ten seats and a very tight last one

Murcia is not small, but its last seat is usually one of the tightest in the country: it has been decided by less than one point in four of the seven elections since 2008, and in 2016 by 2,774 votes. In 2023 the PP won four seats, the PSOE three, Vox two and Sumar one.

With November 29 the split changes. Vox rises to 28.9% in the forecast and Frente Amplio, the left alliance and Sumar’s heir, falls to 5.0%: Sumar’s seat disappears in 92% of simulations. The most likely outcome is PP 4 or 5, Vox 3 or 4 and PSOE 2 or 3. The PP takes the last seat in 42% of simulations, Vox in 33% and the PSOE in 22%.

Soria: two seats and a third contender

Soria elects two members, the minimum for a province, and the effective threshold is 25%. In 2023, the PP and the PSOE won one each, and Soria ¡Ya! (a local “emptied Spain” platform) fell 5,270 votes short of the second with 19.1%. The forecast gives the PP 33.9%, the PSOE 24.0% and Soria ¡Ya! 19.4%, with a very wide interval (from 9% to 35%). The second seat goes to the PSOE in 67% of simulations, to Soria ¡Ya! in 18% and to the PP in 13%.

Teruel: Vox, the PP and Teruel Existe

Teruel elects three. In 2023 the PP won two and the PSOE one, and Teruel Existe (another local “emptied Spain” platform) fell 1,946 votes short of the third. This year Frente Amplio is not running in Teruel, and the forecast gives the PP 32.0%, the PSOE 25.9%, Vox 18.1% and Teruel Existe 15.5%. The third seat goes to Vox in 48% of simulations, to the PP in 21%, to Teruel Existe in 18% and to the PSOE in 13%.

Álava: four seats for four parties

Álava is the extreme example of fragmentation: in 2023 the PSOE, EH Bildu, the PP and the PNV (the Basque nationalists) won one member each. In April 2019 EH Bildu won the last seat by 362 votes over the PP. For November 29, all four are again between 16% and 23% in the forecast, and the question is who is left without a seat or who wins two. The last one goes to the PNV in 34% of simulations, to the PSOE in 23%, to the PP in 21% and to EH Bildu in 20%.

Huesca: the third, between the PP and Vox

In Huesca, with three seats, the last one is between two parties of the same bloc: the third seat goes to Vox in 49% of simulations and to the PP in 41%. It does not change the combined total of the PP and Vox, but it does change how many members each has, and that matters for any negotiation between them. The PSOE keeps its seat in 93% of simulations.

Eight provinces, eight last seats

In six of the eight, the favorite for the last seat is below 50%. And in five, the favorite is a different party from the one that won it in 2023. It is in these provinces, more than in Madrid or Barcelona, that an election night can bring one-seat surprises that, added together, decide majorities.

All the constituencies, with each party’s probabilities, are on our last seat page.

How we calculated it

• Results and margins 2008–2023. Official results from the BOE (Spain’s official gazette) and the D’Hondt allocation reproduced seat by seat; margin: new votes the cheapest rival needed to take the last seat (multi_margins.py).
• Forecast. Today’s forecast simulations by constituency: mean vote share and 95% interval, probability of each number of seats and of the last seat. In Navarre, UPN and the PP run in coalition; in Teruel, with no Frente Amplio candidacy.
• Code. articulo_pequenas.py, in the altnalysis repository.