At stake in this election:     

• 208 seats in the Senate (Senado)

Description of government structure:

• Chief of State: King FELIPE VI (Since 19 June 2014)
• Head of Government: President of the Government Mariano RAJOY (since 21 December 2011)
• Assembly: Spain has a bicameral legislature known as the General Courts (Cortes Generales) consisting of the Senate (Senado) with 266 seats and the Congress of Deputies (Congreso de los Diputados) with 350 seats.

Description of electoral system:

• The King is the hereditary head of government.
• The President of the Government is elected by the parliament.
• In the Senate (Senado), 208 members are elected by plurality vote in multi-member constituencies to serve 4-year terms, and 58 members are appointed by regional legislatures to serve 4-year terms. In the Congress of Deputies (Congreso de los Diputados), 350 members are elected through a closed-list proportional representation system to serve 4-year terms.

Main parties in the electoral race:

• Party: Popular Party / Partido Popular (PP)
  • Leader: Mariano RAJOY
  • Seats won in last election: 136
• Party: Spanish Socialist Workers’ Party / Partido Socialista Obrero Español (PSOE)
  • Leader: Pedro SÁNCHEZ
  • Seats won in last election: 48​
• Party: Catalan Progress Agreement / Entesa Catalonia de Progrés (ECP)
  • Leader: Carles Bonet i REVÉS
  • Seats won in last election: 7
• Party: Basque Nationalist Party / Partido Nacionalista Vasco / Euzko Alderdi Jeltzalea
  • Leader: Andoni ORTUZAR
  • Seats won in last election: 4
• Party: Amaiur
  • Leader: Xabier Mikel ERREKONDO
  • Seats won in last election: 3
• Party: Canary Coalition / Coalición Canaria (CC)
  • Leader: Claudina MORALES
  • Seats won in last election:1

Last election:

• The last election for the Senate (Senado) was held on 20 November 2011. There were 35,779,491 registered voters for the election. The Popular Party won 136 seats (of 208 seats); the Spanish Socialist Workers’ Party won 48 seats; the Convergence and Union Party won 9 seats; the Entesa Catalonia de Progres Party won 7 seats; the Basque Nationalist Party won 4 seats; the AMAIUR Party won 3 seats; and the Canary Coalition won 1 seat.

Population and number of registered voters:

• Population: 48,146,134 (2015 est.)
• Registered voters: 36,514,084 (2014)

Gender Data:

• Female Population: 24,073,067 (2015 est.)
• Is Spain a signatory to CEDAW: Yes (17 July 1980)
• Has Spain ratified CEDAW: Yes (5 January 1984) 
• Gender Quota:  Yes
• Female Candidates in this election: Yes
• Number of Female Legislators: 88 (33%) of 266 seats in the Senate (Senado); 126 (36%) of 350 in the Congress of Deputies (Congreso de los Diputados)
• Human Development Index (HDI) Position: 26
• Social Institutions and Gender Index (SIGI) Categorization: Very Low 

Disability Data:

• Is Spain a signatory to CRPD: Yes (30 March 2007)
• Has Spain ratified CRPD: Yes (3 December 2007)
• Population with a disability: 7,221,920 (2015 est.)