Spanish general election, 1979

Electoral system

The Spanish Cortes Generales were regarded as an imperfect bicameral system. The Congress of Deputies had greater legislative power than the Senate, having the ability to grant or revoke confidence from a Prime Minister and to override Senate vetoes by an absolute majority of votes. Nonetheless, the Senate possessed a few exclusive, yet limited in number functions—such as its role in constitutional amendment—which were not subject to the Congress' override. No electoral law was in force at the time, with election rules for both chambers regulated under a provisional decree.

For the Congress of Deputies, 348 seats were allocated to 50 multi-member districts—each corresponding to a province—, elected using the D'Hondt method and a closed list proportional representation. Ceuta and Melilla elected one member each using plurality voting, for a total of 350 seats. Each district was entitled to an initial minimum of two seats, with the remaining 248 allocated among the 50 provinces in proportion to their populations. A threshold of 3% of valid votes—which included blank ballots—was applied in each constituency, with parties not reaching the threshold not taken into consideration for seat distribution.

For the Senate, each of the 47 peninsular constituencies was allocated four seats. For insular provinces, such as the Balearic and the Canary Islands, districts were the islands themselves, with the larger—Majorca, Gran Canaria and Tenerife—being allocated three seats each, and the smaller—Menorca, Ibiza-Formentera, Fuerteventura, La Gomera, El Hierro, Lanzarote and La Palma—one each. Ceuta and Melilla elected two seats each, for a total of 208 directly elected seats, using an open list partial block voting. Instead of voting for parties, electors would vote for individual candidates. In districts electing four seats, electors could vote for up to three candidates; in those with two or three seats, for up to two candidates; and for one candidate in single-member constituencies. Additionally, autonomous communities could appoint at least one senator each and were entitled to one additional seat per each million inhabitants.

Voting was on the basis of universal suffrage, with all nationals over eighteen and in the full enjoyment of all political rights entitled to vote. Concurrently, nationals meeting the previous criteria and not involved in any cause of ineligibility were eligible for both the Congress and the Senate. Groups of electors were required to obtain the signatures of at least 1/1000 of registered electors—provided that this amount did exceed of 500—in a particular district in order to be able to field candidates.

The Prime Minister had the ability to dissolve the chambers at any given time—either jointly or separately—and call a snap election; otherwise, elected deputies and senators served for four year terms, starting from election day. Additionally, both chambers were to be automatically dissolved in the event of unsuccessful investiture attempts failing to elect a Prime Minister within a two month-period from the first ballot, triggering a snap election likewise.

Opinion polls

Individual poll results are listed in the table below in reverse chronological order, showing the most recent first, and using the date the survey's fieldwork was done, as opposed to the date of publication. If such date is unknown, the date of publication is given instead. The highest percentage figure in each polling survey is displayed with its background shaded in the leading party's colour. In the instance of a tie, the figures with the highest percentages are shaded. Seat projections are displayed in bold and in a different font. The lead column on the right shows the percentage-point difference between the two parties with the highest figures. 176 seats were required for an absolute majority in the Congress of Deputies.