The Centro de Investigaciones Sociológicas (CIS) released its September barometer on Monday, 14 September 2026. The data shows the PSOE leading general election voting estimates with 31% of the vote, while the PP follows in second place with 25.5% support.
The PSOE's lead over the PP has narrowed to 5.5 points, down from a 7.9-point gap recorded in July. Meanwhile, Vox saw its share rise to 16.6% from 15.3%, and Podemos increased to 3.7%, placing the party just two points behind Sumar in the latest projections.
This barometer is the first published since the migratory crisis in Ceuta at the end of July. As the first major polling data following the mass entry of immigrants into the territory, these figures reflect a shifting political landscape across the country.