Election Poll Spain: Results from Ipsos on May 21, 2025

According to data from Sigma Dos, 7 parties are projected to surpass the electoral threshold and enter the Spain parliament: Partido Popular with 112 representatives, PSOE with 104 representatives, Vox with 58 representatives, Unidos Podemos with 39 representatives, Ciudadanos with 13 representatives, Más País with 13 representatives and ERC with 11 representatives.

Spain's Parliament, the Cortes Generales, comprises two chambers: the Congress of Deputies (Congreso de los Diputados) and the Senate (Senado). The Congress of Deputies, with 350 members, is elected through a closed-list proportional representation system. The country is divided into 52 constituencies, corresponding to its provinces and the autonomous cities of Ceuta and Melilla. Seat allocation follows the D'Hondt method. In practice, as many provinces elect only a few deputies, the system often functions more like a majoritarian one, favoring large national parties and robust regional parties.

To enter the Spanish Congress of Deputies, a 3% electoral threshold applies. However, this hurdle is applied at the constituency level, not nationwide. In practice, this 3% threshold holds little sway in most provinces, where the small number of seats available effectively demands a much higher vote share (often exceeding 10% or 15%) to secure a mandate. Only in large constituencies like Madrid or Barcelona does the 3% clause genuinely impact smaller parties.

Forming a government in Spain requires the confidence of the Congress of Deputies. Following consultations with party leaders, the King proposes a candidate for Prime Minister (Presidente del Gobierno). In the first vote, the candidate needs an absolute majority (176 votes). If this fails, a simple majority (more 'yes' than 'no' votes) suffices 48 hours later. While single-party governments long dominated, Spain has evolved into a multi-party system since 2015, necessitating complex coalitions or minority governments with shifting parliamentary support.