Spain's CIS poll gives PSOE 152 seats, stoking fears of a disputed 29N result

Spain's CIS poll gives PSOE 152 seats and sets the stage for a tense 29N night

Less than a week before Spain's general election, the latest barometer from the Centro de Investigaciones Sociológicas (CIS, the state-run polling institute) has put a number on the table that no other poll shares: 152 seats for the PSOE. All other published surveys place the Socialists in the 100 to 110 seat range and give the combined PP and VOX between 195 and 210 seats. The distance between the two scenarios is around fifty seats, and it is that gap that has turned election night on 29N into a powder keg of incompatible expectations.

The problem is not just statistical. It is one of legitimacy. If the CIS is right, a majority of private polls will have failed spectacularly. If the CIS is wrong, the public body answerable to the government will have manufactured an expectation that its own voters may perceive as a fraud. In both cases, there is a bloc of the population that will not accept the result. Half the country, whatever colour the count turns out to be, will have grounds to cry foul.

Why the Tezanos-led CIS breaks with every forecast

It is the magnitude of the deviation that has set off every alarm. We are not talking about a two- or three-seat difference, the usual margin within which polls move. We are talking about a 50-seat gap between the CIS and the consensus of private polls. In 2023, discrepancies stayed within a range of around ten seats; now the figure is five times larger.

Some argue that the CIS is a propaganda tool and that Tezanos has spent three years publishing the same poll with minor tweaks. Others maintain that private firms serve right-wing interests and that the public body is the only one with no commercial incentives. The debate over sample size — the n figure almost nobody publishes alongside the chart — is buried beneath the political battle.

The practical effect is twofold. On the one hand, it may demobilise right-wing voters, who take for granted a victory the polls promise them. On the other, it may mobilise left-wing voters with the hope of a result that no other source supports. The poll as a campaign weapon, not as a thermometer.

The electoral roll, postal voting and the shadow of vote-rigging

Distrust in the electoral system is nothing new, but this election has given it fertile ground. Behind the debate loom the figures of 1.6 million young people voting for the first time and 1.7 million older people who have died since the last election. Add to that the legal dispute over the Ley de Nietos (the 'Grandchildren Law', a Spanish statute on citizenship for descendants of exiles): according to circulating reports, the Supreme Court has allegedly warned the government that 163,000 naturalised citizens could vote without having proven they are descendants of exiles, and the government says there was no time to amend the electoral roll before the election.

That cocktail — an electoral roll under review, postal voting under suspicion, a public body inflating expectations — fuels the fraud thesis at both ends of the political spectrum. The difference from 2023, when talk of rigging already centred on a handful of seats, is that the disputed margin is now five times larger. A close result will be read as theft by whichever side feels wronged.

Who believes the CIS and who laughs at it

The divide is not only political, it is one of digital ecosystems. On one social network, posts celebrate the barometer as a rebuke to the entire private polling industry; on another, the CIS is the object of mockery and memes. Two audiences, two parallel realities, one single figure. The information bubble does the rest: each bloc consumes the version that confirms its suspicions.

The detail that worries analysts most is that the CIS arrives after four years of management with accumulated errors and the wear and tear of a long cycle. The Segarro campaign to get 250,000 naturalised citizens to vote for the PSOE, according to circulating reports, adds one more element to the sense that the result is being contested before the votes are even counted.

What could happen on the night of 29N

Scenario A is a PSOE win. If that happens, 99% of private polls will have failed and the streets will respond with the same logic as in 2023, only louder. Scenario B is a win for PP and VOX. Then the electorate that trusted the CIS will feel robbed, and the anti-fascist alert will have one more reason to take to the streets.

The paradox is that both sides have been trained never to accept defeat. The CIS is not the cause of the problem, but it is the trigger that has turned an election night into a test of the institutions' credibility. With these ingredients, the count on 29N will not be the end of the campaign. It will be the beginning of the next one.