The CIS barometer corresponding to April 2026 draws a scenario of clear advantage for the PSOE. The socialists reach 36.4% of voting intention, which represents a notable increase compared to the previous month and allows them to open a gap of almost 13 points over the PP, which stands at around 23.5%.
This is the largest margin between both parties in recent months and consolidates the PSOE's position as the leading force in voting intention.
Vox remains the third force and Sumar continues to decline
Behind the two big parties, Vox appears as the third force with 14.7%, although with a slight downward trend.
In the space of the alternative left, Sumar continues to lose support and stands at 5.8%, while Podemos hovers around 2%, confirming the fragmentation of this bloc.
A leap by the PSOE driven by the fall of its partners
The rise of the PSOE is largely explained by the transfer of votes from other left-wing forces, especially Sumar and Podemos, and to a lesser extent by the retreat of Vox.
Pedro Sánchez's party thus leads the biggest growth of the month, with an increase of several points compared to March that allows it to widen the gap with the PP.
Context: judicial pressure and political climate of April
The CIS fieldwork was carried out in a context marked by several political and judicial factors, including the current relevance of cases such as Kitchen or Koldo and movements in the left-wing space.
This scenario coincides with the socialist rebound that the poll reflects.
The PSOE signs its best data in years
With this result, the PSOE achieves its best record in recent CIS barometers and reinforces its dominant position in the 2026 series.
The poll consolidates a scenario in which the socialists widen their lead, while the PP remains stable without managing to close the gap and the left-wing bloc appears increasingly fragmented.