Congress of Deputies

The Congress of Deputies (Spanish: Congreso de los Diputados) is the lower house of the Cortes Generales, Spain's legislative branch, the upper house being the Senate. The Congress meets in the Palace of the Parliament (Palacio de las Cortes) in Madrid.

Congress has 350 members elected from fifty-two constituencies (the fifty provinces and two autonomous cities) using closed list D'Hondt proportional representation. Deputies serve four-year terms. The presiding officer and speaker is the President of the Congress of Deputies, who is elected by the members at the first sitting of Congress after an election.

The two principal bodies in Congress are parliamentary groups and parliamentary committees (Spanish: comisiones). All MPs are required to be members of a parliamentary group, the institutionalised form of political parties. Groups act with one voice represented by their spokesperson. In other words, the Spanish Parliament is a parliament of groups, not individual MPs who are constrained to act only as part of the group. MPs can only act autonomously when submitting oral or written questions.

As a result of the 2019 general election, there were 168 female deputies or 48% of all members, making Spain the European country with the highest percentage of women in parliament, surpassing Sweden and Finland; however, the share decreased to a 44.3% after the elections in 2023.

Section 68.1 of the Spanish Constitution establishes that the Congress of Deputies must be composed of at least 300, and no more than 400 deputies. At present, the house has 350 deputies which is determined by the 1985 Electoral Act.

The Spanish Constitution establishes that the deputies are chosen by universal, free, equal, direct, and secret suffrage. The election is held every four years or earlier in case of snap election. The members of the Congress are elected by proportional representation with closed lists in each constituency.

There are 52 constituencies for the Congress of Deputies corresponding to the 50 provinces of Spain and two autonomous cities (Ceuta and Melilla). According to Spanish electoral law, the number of seats in each constituency can change in each election and it is specified when writs of election are issued. Each province is guaranteed a minimum allocation of two seats, and one seat each for Ceuta and Melilla for a total of 102 seats. The remaining 248 seats are allocated proportionally according to the population using the Hare quota.

After the General Election, seats are assigned to the electoral lists in each constituency separately, using the D'Hondt method; parties receive seats in approximate proportion to the number of votes each received in the constituency. A strictly proportional system would result in fractional seats; the D'Hondt method resolves this by favoring parties receiving larger votes.