Can the PSOE Win the Election? The Catalan, Andalusian and Basque Route, and Why It Would Not Be Enough to Govern

Today the forecast gives the PSOE an 18% chance of being the most-voted party and a 15% chance of winning more seats than the PP. One route would be to sweep Catalonia as in 2008, tie the PP in Andalusia, stay close in Madrid and add borrowed votes from Bildu and the PNV in the Basque Country. We ran the numbers. Even with all of that, the PSOE would tie the PP in votes but would outscore it in seats in only 35% of simulations, because most of those votes would come from its allies rather than the PP. And the PP and Vox would still add up to an absolute majority in 94%. Moreover, a shift toward the PSC like the one in 2008 has no basis in today's polls: at most, half of it would fit.

27 October 2026 · Miguel · Leer en español

Where we stand

The October 27 forecast gives the PP a median lead of 4.0 points over the PSOE. In 95% of simulations, the gap runs from 4.8 points in favor of the PSOE to 12.6 in favor of the PP. The PSOE is the most-voted party in 18% of simulations and has more seats than the PP in 15%. It is not a remote possibility, but it is the less likely of the two.

The question in this article is more specific: what would have to happen for the PSOE to finish first, in votes and in seats, even narrowly and without being able to govern. There are two ways to answer it.

What the model says: where the PSOE wins when it wins

In the 7,302 simulations (out of 50,000) in which the PSOE wins more seats than the PP, the map does not change shape, it only shifts. All regions move toward the PSOE at once, because what decides elections is mostly the national climate:

• Catalonia: the PSC goes from a 16-point lead over the PP to 21.
• Andalusia: from nearly 7 points behind to an exact tie.
• Madrid: from 13.5 points behind to 7.
• Basque Country: from 10 points ahead to 14.
• Spain overall: from 4 points behind to 2.5 ahead.

In other words, when the PSOE wins in the model, it does so through a general movement of about six and a half points in the gap with the PP. It does not do it by sweeping a single region.

The regional route: the hypothesis, worked out

There is another way to frame it, as a territorial path. It has four pieces, and the rest of Spain stays as in the forecast:

1. Catalonia as in 2008. In 2008 the PSC took 45.4% of the vote in Catalonia and 25 of 47 members of Congress. Today the forecast gives it 31.5% and 18 members. In the hypothesis it reaches 45% with borrowed votes from ERC, Junts and the Comuns: about 544,000 votes.
2. A tie in Andalusia. The forecast gives the PP 31.7% and the PSOE 25.0%. In the hypothesis they tie, with half the gap recovered from the PP and the other half from Adelante Andalucía, Frente Amplio and Podemos: about 316,000 votes.
3. Madrid, within ten points. The forecast gives the PP 37.5% and the PSOE 24.0%, a gap of thirteen and a half points. In the hypothesis it narrows to ten: about 68,000 votes, half of them from the PP.
4. Six members of Congress in the Basque Country. The PSOE goes from five to six of the 18 Basque seats, with votes from Bildu (two thirds) and the PNV (one third): about 19,000 votes.

The result

With the four pieces, the PSOE would tie the PP in votes (30.3% each; it would be the most-voted party in half of simulations). It would gain about 14 seats, reaching 123. But the PP would stay at 128. The PSOE would outscore it in seats in only 35% of simulations.

Why it is not enough

The reason is arithmetic, and it has to do with where the votes come from:

• In Catalonia, the “borrowed” votes come from the PSOE’s allies, not from the PP. The 544,000 votes needed to return to 45% come from ERC, Junts and the Comuns. The PSC gains about nine members of Congress (from 18 to 27), but ERC drops from 8 to 3 and Junts from 4 to 1. The PP keeps its 8 Catalan seats. It is the biggest piece and the one that brings the PSOE least closer to the PP, because it only redistributes seats within the same bloc.
• The same happens in the Basque Country: one more seat for the PSOE is one fewer for Bildu or the PNV.
• Only Andalusia and Madrid take seats from the PP. The PSOE gains three Andalusian seats (from 18 to 21) and the PP loses three (from 24 to 21). In Madrid the PSOE gains one and the PP loses one.

Finishing first requires, above all, taking votes from the PP. And the regional route does so in only two of its four pieces.

How much more it would take

If the PSOE also won back a little vote from the PP in the rest of Spain, outside those four regions:

With one more point shifted from the PP to the PSOE in the rest of Spain, the PSOE would tie the PP in seats (126 each) and would be first in almost half of simulations (48%). With a point and a half, in 55%; with three points, in 75%.

Is a shift like 2008’s sustainable?

The Catalan piece weighs the most in the hypothesis, and it is worth asking whether it has any basis. In 2008 the PSC rose from 39.5% to 45.4% and ERC collapsed from 15.9% to 7.8%. It was a shift toward the tactical vote against the PP, with ERC worn down by the tripartite government. In the Basque Country, the PSE won that year with 38% of the vote, but the abertzale left had no legal party: its vote went to abstention or to blank and void ballots. That framework does not exist today.

We measured the margin with the latest CEO barometer (May and October 2026). Among Catalans who plan to vote for ERC, Junts or the Comuns in the general election:

• ERC: 22% have the PSC as their second choice in the Parlament, and almost half (49%) rate Pedro Sánchez 6 or higher. Only 13% voted for the PSOE in 2023.
• Junts: only 7% have the PSC as their second choice, and a third rate Sánchez favorably.
• Comuns: 25% have the PSC as their second choice and 49% rate Sánchez favorably.

If everyone who has the PSC as a second choice gave it their vote, something that never happens in full, the PSC would gain about six points in Catalonia. It would reach 37–38%, not 45%. Reaching 45% would take twice as much: four out of ten ERC, Junts and Comuns voters would have to switch, including many who do not even consider it their second choice. In the Basque Country, Bildu is now an established party, with close to a quarter of the vote, and the PNV keeps a loyal electorate. One more seat for the PSE is plausible; the 38% of 2008 is not.

The conclusion is that the strong version of the hypothesis, a shift “like 2008,” has no support in current data. The moderate version, with the PSC around 37% and one more seat in the Basque Country, is sustainable, but it delivers less than half the seats of the full hypothesis, and almost all of them at the expense of the PSOE’s allies.

First is not governing

Even in the best of those scenarios, the PP and Vox would still add up to an absolute majority. With the full hypothesis, in 94% of simulations; with three more points in the rest of Spain, in 81%. The sum of the PSOE, Frente Amplio and Podemos would remain at a median of 132 seats. The 2023 investiture partners would add up to 152: the Catalan route fattens the PSOE but thins ERC and Junts, which are also part of that sum. Being the most-voted party would have political value, but it would not deliver the 176 seats.

Is it realistic?

• Catalonia at 45% is the hardest part. So far this century it has happened only in 2008, with the PSOE in government and ERC at a low point. Today the PSC is at 31.5% in the forecast, and reaching 45% requires four out of ten ERC, Junts and Comuns voters to lend it their vote.
• The tie in Andalusia requires a comeback of nearly seven points over the forecast, in a region where the PP took 41.6% in the May regional election.
• Madrid and the Basque Country are smaller moves and fall within the normal margin of error.

Taken together, the four pieces are an optimistic scenario for the PSOE, not the central one. And even so they would leave it close to first place, not safely above it. The shortest path for the PSOE is not the regional one, but the one the model itself shows: cutting the gap with the PP by about six and a half points across all of Spain at once.

How we calculated it

• Forecast. The altnalysis forecast of October 27 (50,000 simulations). The votes in each simulation are rebuilt with the simulated turnout and the 2026 resident electorate, and seats are reallocated with D’Hondt and the 3% threshold.
• Hypothesis. In each simulation, the votes needed are moved so that the PSC reaches 45% in Catalonia (from ERC, Junts and the Comuns, in proportion to their vote), the PSOE ties the PP in Andalusia (half from the PP and half from Adelante, Frente Amplio and Podemos), the PP − PSOE gap in Madrid falls to ten points (half from the PP and half from Frente Amplio and Podemos) and the PSOE wins at least six Basque seats (from Bildu and the PNV). The remaining provinces are untouched. The figures for votes moved are medians.
• Simulations with the PSOE first. These are the 7,302 in which the PSOE has more seats than the PP in the forecast, with no added hypothesis.
• Code. analisis_psoe_primero.py, in the altnalysis repository.