A regional election was held in Castile and León on 10 June 1987 to elect the 2nd of the autonomous community. All 84 seats in the were up for election. It was held concurrently with regional elections in twelve other autonomous communities and local elections all across Spain, as well as the 1987 European Parliament election.

Expectations for the ruling Spanish Socialist Workers' Party (PSOE) were low after the resignation in October 1986 of former president Demetrio Madrid, besieged by a judicial investigation on the alleged fraudulent sale of a former textile company of his property and by internal opposition from within his party. The election saw both the PSOE and the opposition People's Alliance (AP)—which ran on its own after the break up of the People's Coalition with the People's Democratic Party (PDP) and the Liberal Party (PL) the previous year—lose ground to the Democratic and Social Centre (CDS) which, with 18 seats and 19.4% of the share, scored the best result for a third party in a Castilian-Leonese regional election to date. The PDP was able to win one seat by Segovia, with Castile and León becoming one of the only two autonomous communities—the other being Navarre—in which the party was able to secure parliamentary representation. In Burgos, a breakway party, Independent Solution (SI), formed by the incumbent mayor of its capital city, José María Peña San Martín, obtained one seat in the regional .

As a result of the election, the support of PDP and SI procurators and the decisive abstention of the CDS, AP candidate José María Aznar was able to become President of the Regional Government of Castile and León, replacing Socialist José Constantino Nalda and starting an uninterrupted stay of over three decades in power for AP and its successor, the People's Party (PP). Aznar's presidency would last until 1989, when he would resign to Jesús Posada in order to become the PP's national leader and, in 1996, prime minister of Spain.

Overview Under the 1983 Statute of Autonomy, the Cortes of Castile and León was the unicameral legislature of the homonymous autonomous community, having legislative power in devolved matters, as well as the ability to grant or withdraw confidence from a regional president.. The electoral and procedural rules were supplemented by national law provisions..

Date The term of the of Castile and León expired four years after the date of its previous ordinary election. The election decree was required to be issued no later than 25 days before the scheduled expiration date of parliament and published on the following day in the Official Gazette of Castile and León (BOCYL), with election day taking place between 54 and 60 days after the decree's publication.; ( by ). The previous election was held on 8 May 1983, which meant that the chamber's term would have expired on 8 May 1987. The election decree was required to be published in the BOCYL no later than 14 April 1987, setting the latest possible date for election day on 13 June 1987.

The of Castile and León could not be dissolved before the expiration date of parliament, except in the event of an investiture process failing to elect a regional president within a two-month period from the first ballot. In such a case—provided this did not happen during the last year of parliament before its planned expiration—the were to be automatically dissolved and a snap election called, with elected lawmakers serving the remainder of its original four-year term..

The election to the of Castile and León was officially called on 14 April 1987 with the publication of the corresponding decree in the BOCYL, setting election day for 10 June and scheduling for the chamber to reconvene on 2 July..

Electoral system Voting for the was based on universal suffrage, comprising all Spanish nationals over 18 years of age, registered in Castile and León and with full political rights, provided that they had not been deprived of the right to vote by a final sentence, nor were legally incapacitated.; ( by ).

The of Castile and León had three seats per each multi-member constituency—corresponding to the provinces of Ávila, Burgos, León, Palencia, Salamanca, Segovia, Soria, Valladolid and Zamora—plus one additional seat per 45,000 inhabitants or fraction above 22,500. All were elected using the D'Hondt method and closed-list proportional voting, with a three percent-threshold of valid votes (including blank ballots) in each constituency.; . The use of this electoral method resulted in a higher effective threshold depending on district magnitude and vote distribution.

As a result of the aforementioned allocation, each constituency was entitled the following seats:.

Seats Constituencies 15 León 14 Valladolid 11 Burgos, Salamanca 8 Zamora 7 Ávila, Palencia 6 Segovia 5 Soria

The law did not provide for by-elections to fill vacant seats; instead, any vacancies arising after the proclamation of candidates and during the legislative term were filled by the next candidates on the party lists or, when required, by designated substitutes. ( by ).

Outgoing parliament The table below shows the composition of the parliamentary groups in the chamber at the time of the election call.

+ Parliamentary composition in April 1987 Groups Parties Legislators Seats Total Socialist Parliamentary Group PSOE 41 41 People's Parliamentary Group AP 31 36 PDP 5 Mixed Parliamentary Group CDS 1 7 PANCAL 1 INDEP 5

Parties and candidates The electoral law allowed for parties and federations registered in the interior ministry, alliances and groupings of electors to present lists of candidates. Parties and federations intending to form an alliance were required to inform the relevant electoral commission within 10 days of the election call, whereas groupings of electors needed to secure the signature of at least one percent of the electorate in the constituencies for which they sought election, disallowing electors from signing for more than one list. ( by ).

Below is a list of the main parties and alliances which contested the election:

Candidacy Parties andalliances Leading candidate Ideology Previous result Vote % Seats PSOE Juan José Laborda Social democracy 44.4% AP José María Aznar ConservatismNational conservatism 39.7% PDP Rafael de las Heras Christian democracy CDS Carlos Sánchez-Reyes CentrismLiberalism 6.0% IU Antonio Herreros SocialismCommunism 3.2% SI Tomás Cortés ConservatismLocalism colspan="2"

Opinion polls The tables below list opinion polling results in reverse chronological order, showing the most recent first and using the dates when the survey fieldwork was done, as opposed to the date of publication. Where the fieldwork dates are 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. If a tie ensues, this is applied to the figures with the highest percentages. The "Lead" column on the right shows the percentage-point difference between the parties with the highest percentages in a poll.

Voting intention estimates The table below lists weighted voting intention estimates. Refusals are generally excluded from the party vote percentages, while question wording and the treatment of "don't know" responses and those not intending to vote may vary between polling organisations. When available, seat projections determined by the polling organisations are displayed below (or in place of) the percentages in a smaller font; 43 seats were required for an absolute majority in the Cortes of Castile and León.

Polling firm/Commissioner Fieldwork date Sample size Turnout Lead 1987 regional election 10 Jun 1987 73.2 34.0 – 19.4 3.8 – 34.4 2.4 1.3 0.4 Government of Castile and León 27 May 1987??? –? – –?? –? Demoscopia/El País 22–26 May 1987? 60 29.4 – 21.3 5.3 – 36.8 2.0 – 7.4 1986 general election 22 Jun 1986 72.8 38.8 35.8 17.5 2.5 1.3 – 3.0 Edis 28 Jul 1985?? 49.7 30.7 9.0 <5.0 – – 19.0 1983 regional election 8 May 1983 69.8 44.4 39.7 6.0 3.2 2.7 – 4.7

Voting preferences The table below lists raw, unweighted voting preferences.

Polling firm/Commissioner Fieldwork date Sample size Lead 1987 regional election 10 Jun 1987 24.5 – 13.9 2.7 – 24.7 1.8 1.0 31.9 0.2 CIS 2–5 Jun 1987 4,603 22.4 – 12.6 2.3 – 18.9 0.7 – 36.6 4.9 3.5 CIS 9–16 May 1987 6,566 22.7 – 11.6 1.7 0.1 16.7 0.6 – 39.5 5.5 6.0 CIS 14–23 Apr 1987 6,566 23.3 – 10.8 1.7 0.1 14.1 0.7 – 42.7 5.3 9.2 CIS 12–22 Mar 1987 5,652 25.0 – 11.0 2.0 0.0 13.0 0.0 – 41.0 6.0 12.0 CIS 1 Dec 1986 4,496 29.8 – 10.1 1.7 0.2 13.2 0.5 – 36.1 6.5 16.6 1986 general election 22 Jun 1986 27.9 25.8 12.6 1.8 1.0 – 26.6 2.1 CIS 1 Feb–1 Mar 1986 2,501 26.5 13.3 3.1 1.4 0.4 – 42.6 10.9 13.2 1983 regional election 8 May 1983 30.5 27.3 4.1 2.2 1.9 – 30.2 3.2

Victory preferences The table below lists opinion polling on the victory preferences for each party in the event of a regional election taking place.

Polling firm/Commissioner Fieldwork date Sample size Other/None Lead CIS 2–5 Jun 1987 4,603 27.8 16.8 2.7 – 23.8 0.8 2.1 26.0 4.0 CIS 9–16 May 1987 6,566 29.5 14.8 2.0 0.1 21.0 0.5 0.9 31.2 8.5 CIS 14–23 Apr 1987 6,566 29.2 14.7 2.0 0.1 18.0 0.7 1.2 33.8 11.2 CIS 12–22 Mar 1987 5,652 29.0 14.0 2.0 0.0 17.0 1.0 1.0 36.0 12.0 CIS 1 Dec 1986 4,496 35.8 13.3 2.0 0.2 16.4 0.6 1.7 30.0 19.4

Victory likelihood The table below lists opinion polling on the perceived likelihood of victory for each party in the event of a regional election taking place.

Polling firm/Commissioner Fieldwork date Sample size Other/None Lead CIS 2–5 Jun 1987 4,603 42.4 6.0 0.3 – 12.1 0.2 0.2 38.8 30.3 CIS 9–16 May 1987 6,566 40.5 6.3 0.1 0.0 9.9 0.2 0.2 42.7 30.6 CIS 14–23 Apr 1987 6,566 40.5 6.0 0.1 0.0 7.7 0.3 0.3 45.1 32.8 CIS 12–22 Mar 1987 5,652 41.0 5.0 0.0 0.0 7.0 0.0 0.0 47.0 34.0 CIS 1 Dec 1986 4,496 54.8 3.0 0.1 0.0 5.5 0.1 0.1 36.3 49.3

Preferred President The table below lists opinion polling on leader preferences to become president of the Regional Government of Castile and León.

Polling firm/Commissioner Fieldwork date Sample size Other/None/Notcare Lead CIS 2–5 Jun 1987 4,603 – 19.7 18.0 – – 3.9 1.8 – 1.9 11.0 43.7 1.7 CIS 9–16 May 1987 6,566 – 10.1 9.0 – – 0.7 1.1 – 2.2 16.5 60.4 1.1 CIS 14–23 Apr 1987 6,566 10.2 4.4 6.1 1.3 1.3 – – 8.3 – 16.7 51.9 1.9

Results Overall + ← Summary of the 10 June 1987 Cortes of Castile and León election results → Parties and alliances Popular vote Seats Votes % ±pp Total +/− People's Alliance (AP)1 493,488 34.36 n/a 32 +1 Spanish Socialist Workers' Party (PSOE) 488,469 34.01 −10.36 32 −10 Democratic and Social Centre (CDS) 278,253 19.37 +13.41 18 +16 United Left (IU)2 54,676 3.81 +0.58 0 ±0 People's Democratic Party (PDP)1 35,080 2.44 n/a 1 −5 Independent Solution (SI) 19,282 1.34 New 1 +1 Workers' Party of Spain–Communist Unity (PTE–UC) 11,943 0.83 New 0 ±0 Leonesist Union (UNLE) 8,960 0.62 New 0 ±0 Party of El Bierzo (PB) 5,387 0.38 +0.07 0 ±0 Nationalist Party of Castile and León (PNCL–PANCAL)1 5,190 0.36 n/a 0 −1 Regionalist Party of the Leonese Country (PREPAL) 4,090 0.28 −2.23 0 ±0 Humanist Platform (PH) 3,934 0.27 New 0 ±0 Liberal Party (PL)1 2,213 0.15 n/a 0 −1 Spanish Phalanx of the CNSO (FE–JONS) 1,828 0.13 New 0 ±0 Spanish Ruralist Party (PRE) 749 0.05 New 0 ±0 Liberal Democratic Party (PDL) n/a n/a −2.72 0 −1 Blank ballots 22,690 1.58 +0.62 Total 1,436,232 84 ±0 Valid votes 1,436,232 98.28 −0.23 Invalid votes 25,154 1.72 +0.23 Votes cast / turnout 1,461,386 73.15 +3.31 Abstentions 536,307 26.85 −3.31 Registered voters 1,997,693 Sources

Distribution by constituency