The constituency was created as per the
Political Reform Law and was first contested in the
1977 general election. The Law provided for the
provinces of Spain to be established as multi-member districts in the
Congress of Deputies, with this regulation being maintained under the
Spanish Constitution of 1978. Additionally, the Constitution requires for any modification of the provincial limits to be approved under an
organic law, needing an
absolute majority in the
Cortes Generales. Voting is on the basis of
universal suffrage, which comprises all nationals over 18 years of age and in full enjoyment of their political rights. The only exception was in 1977, when this was limited to nationals
over 21 years of age and in full enjoyment of their political
and civil rights. Amendments to the electoral law in 2011 required for
Spaniards abroad to
apply for voting before being permitted to vote, a system known as "begged" or expat vote (), which was abolished in 2022. 348 seats are elected using the
D'Hondt method and a
closed list proportional representation, with an
electoral threshold of three percent of valid votes—which includes blank ballots—being applied in each constituency. Each provincial constituency is entitled to an initial minimum of two seats, with the remaining 248 being distributed in proportion to their populations.
Ceuta and
Melilla are allocated the two remaining seats, which are elected using
plurality voting. The use of the electoral method may result in an
effective threshold based on the
district magnitude and the distribution of votes among candidacies. The electoral law allows for
parties and
federations registered in the
interior ministry,
coalitions and
groupings of electors to present lists of candidates. Parties and federations intending to form a coalition ahead of an election are required to inform the relevant Electoral Commission within ten days of the election call—fifteen before 1985—whereas groupings of electors need to secure the signature of at least one percent of the electorate in the constituencies for which they seek election—one permille of the electorate, with a compulsory minimum of 500 signatures, until 1985—disallowing electors from signing for more than one list of candidates. Also since 2011, parties, federations or coalitions that have not obtained a mandate in either chamber of the Cortes at the preceding election are required to secure the signature of at least 0.1 percent of electors in the aforementioned constituencies. ==Deputies==