# Biscay (Basque Parliament constituency)

Biscay (Basque: Bizkaia, Spanish: Vizcaya) is one of the three constituencies (Spanish: circunscripciones) represented in the Basque Parliament, the regional legislature of the Basque Autonomous Community. The constituency currently elects 25 deputies. Its boundaries correspond to those of the Spanish province of Biscay. The electoral system uses the D'Hondt method and a closed-list proportional representation, with a minimum threshold of three percent.

## Electoral system

The constituency was created as per the Statute of Autonomy for the Basque Country of 1979 and was first contested in the 1980 regional election. The Statute provided for the three provinces in the Basque Country—Álava, Biscay and Gipuzkoa—to be established as multi-member districts in the Basque Parliament, with this regulation being maintained under the 1983 and 1990 regional electoral laws. Each constituency is allocated a fixed number of 25 seats each, to provide for an equal representation of the three provinces in Parliament as required under the regional Statute. The exception was the 1980 election, when this number was 60.
Voting is on the basis of universal suffrage, which comprises all nationals over eighteen, registered in the Basque Country and in full enjoyment of their political rights. Amendments to the electoral law in 2011 required for Basques abroad to apply for voting before being permitted to vote, a system known as "begged" or expat vote (Spanish: Voto rogado) which was abolished in 2022. 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, until 1983 and from 1990 includes blank ballots; also and until a 2000 reform, the threshold was set at five percent—being applied in each constituency. The use of the D'Hondt method may result in a higher effective threshold, depending on the district magnitude.
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-thousandth of the electorate, with a compulsory minimum of 500 signatures, until 1983; and only the signature of 500 electors from 1983 to 1990—disallowing electors from signing for more than one list of candidates.

## Deputies

Deputies 1980–present :
| Key to parties  HB  EH  EHAK  EH Bildu  EH Bildu  EPK  IU/EB  EB–B  Elkarrekin Podemos  Aralar  EE  PSE/PSE–EE  EA  PNV/PNV–EA  UCD  PP+Cs  PP  CP  AP/AP–PL |||
| Parliament | Election | Distribution |
| 1st | 1980 | 4 1 1 3 9 1 1 |
| 2nd | 1984 | 3 2 6 12 2 |
| 3rd | 1986 | 4 3 6 3 8 1 |
| 4th | 1990 | 4 2 5 2 10 2 |
| 5th | 1994 | 3 2 4 2 10 4 |
| 6th | 1998 | 4 1 5 1 9 5 |
| 7th | 2001 | 2 1 4 12 6 |
| 8th | 2005 | 2 1 6 11 5 |
| 9th | 2009 | 1 8 12 4 |
| 10th | 2012 | 6 5 11 3 |
| 11th | 2016 | 5 4 3 11 2 |
| 12th | 2020 | 6 2 3 12 2 |
| 13th | 2024 | 8 4 11 2 |

## Elections
### 2024 regional election

Summary of the 21 April 2024 Basque Parliament election results in Biscay :
| Parties and alliances | Parties and alliances | Popular vote | Popular vote | Popular vote | Seats | Seats |
| Parties and alliances | Parties and alliances | Votes | % | ±pp | Total | +/− |
| | Basque Nationalist Party (EAJ/PNV) | 223,118 | 39.08 | –3.08 | 11 | –1 |
| | Basque Country Gather (EH Bildu) | 161,486 | 28.28 | +4.58 | 8 | +2 |
| | Socialist Party of the Basque Country–Basque Country Left (PSE–EE (PSOE)) | 79,575 | 13.94 | +0.47 | 4 | +1 |
| | People's Party (PP)$^1$ | 51,644 | 9.04 | +2.25 | 2 | ±0 |
| | Unite (Sumar)$^2$ | 19,155 | 3.35 | n/a | 0 | ±0 |
| | United We Can–Green Alliance (Podemos/Ahal Dugu–AV)$^2$ | 12,738 | 2.23 | n/a | 0 | –2 |
| | Vox (Vox) | 10,822 | 1.90 | +0.04 | 0 | ±0 |
| | Animalist Party with the Environment (PACMA)$^3$ | 2,827 | 0.50 | –0.09 | 0 | ±0 |
| | Blank Seats to Leave Empty Seats (EB/AZ) | 1,260 | 0.22 | –0.01 | 0 | ±0 |
| | For a Fairer World (PUM+J) | 920 | 0.16 | +0.03 | 0 | ±0 |
| | To Be (Izan) | 780 | 0.14 | New | 0 | ±0 |
| | Communist Party of the Workers of Spain (PCTE) | 666 | 0.12 | ±0.00 | 0 | ±0 |
| | Humanist Party (PH) | 475 | 0.08 | +0.02 | 0 | ±0 |
| Blank ballots | Blank ballots | 5,528 | 0.96 | +0.01 | | |
| Total | Total | 570,994 | | | 25 | ±0 |
| Valid votes | Valid votes | 570,994 | 99.24 | +0.06 | | |
| Invalid votes | Invalid votes | 4,371 | 0.76 | –0.06 | | |
| Votes cast / turnout | Votes cast / turnout | 575,365 | 60.83 | +10.43 | | |
| Abstentions | Abstentions | 370,513 | 39.17 | –10.43 | | |
| Registered voters | Registered voters | 945,878 | | | | |
| Sources |||||||
| Footnotes: $^1$ People's Party results are compared to People's Party+Citizens totals in the 2020 election.$^2$ Within the United We Can–United Left alliance in the 2020 election.$^3$ Animalist Party with the Environment results are compared to Animalist Party Against Mistreatment of Animals totals in the 2020 election. |||||||

### 2020 regional election

Summary of the 12 July 2020 Basque Parliament election results in Biscay :
| Parties and alliances | Parties and alliances | Popular vote | Popular vote | Popular vote | Seats | Seats |
| Parties and alliances | Parties and alliances | Votes | % | ±pp | Total | +/− |
| | Basque Nationalist Party (EAJ/PNV) | 200,339 | 42.16 | +0.35 | 12 | +1 |
| | Basque Country Gather (EH Bildu) | 112,619 | 23.70 | +6.24 | 6 | +1 |
| | Socialist Party of the Basque Country–Basque Country Left (PSE–EE (PSOE)) | 64,001 | 13.47 | +1.82 | 3 | ±0 |
| | United We Can–United Left (Podemos/Ahal Dugu, Ezker Anitza–IU) | 40,453 | 8.51 | –6.24 | 2 | –2 |
| | People's Party+Citizens (PP+Cs)$^1$ | 32,248 | 6.79 | –4.79 | 2 | ±0 |
| | Vox (Vox) | 8,815 | 1.86 | New | 0 | ±0 |
| | Equo Greens–Basque Country Greens (Equo Berdeak–Verdes) | 5,533 | 1.16 | New | 0 | ±0 |
| | Animalist Party Against Mistreatment of Animals (PACMA/ATTKAA) | 2,797 | 0.59 | –0.21 | 0 | ±0 |
| | Blank Seats (EB/AZ) | 1,079 | 0.23 | +0.07 | 0 | ±0 |
| | Zero Cuts–The Greens–Municipalists (Recortes Cero–LV–M) | 676 | 0.14 | –0.08 | 0 | ±0 |
| | For a Fairer World (PUM+J) | 613 | 0.13 | New | 0 | ±0 |
| | Communist Party of the Workers of the Basque Country (PCTE/ELAK) | 549 | 0.12 | New | 0 | ±0 |
| | Free for the Basque Country (LxE/EaL) | 359 | 0.08 | New | 0 | ±0 |
| | Humanist Party (PH) | 279 | 0.06 | ±0.00 | 0 | ±0 |
| | Foralist League (LFF) | 258 | 0.05 | New | 0 | ±0 |
| Blank ballots | Blank ballots | 4,524 | 0.95 | +0.34 | | |
| Total | Total | 475,142 | | | 25 | ±0 |
| Valid votes | Valid votes | 475,142 | 99.18 | –0.38 | | |
| Invalid votes | Invalid votes | 3,916 | 0.82 | +0.38 | | |
| Votes cast / turnout | Votes cast / turnout | 479,058 | 50.40 | –10.08 | | |
| Abstentions | Abstentions | 471,506 | 49.60 | +10.08 | | |
| Registered voters | Registered voters | 950,564 | | | | |
| Sources |||||||
| Footnotes: $^1$ People's Party+Citizens results are compared to the combined totals of People's Party and Citizens–Party of the Citizenry in the 2016 election. |||||||

### 2016 regional election

Summary of the 25 September 2016 Basque Parliament election results in Biscay :
| Parties and alliances | Parties and alliances | Popular vote | Popular vote | Popular vote | Seats | Seats |
| Parties and alliances | Parties and alliances | Votes | % | ±pp | Total | +/− |
| | Basque Nationalist Party (EAJ/PNV) | 238,581 | 41.81 | +3.87 | 11 | ±0 |
| | Basque Country Gather (EH Bildu) | 99,610 | 17.46 | –3.74 | 5 | –1 |
| | United We Can (Podemos, Ezker Anitza–IU, Equo)$^1$ | 84,195 | 14.75 | +11.33 | 4 | +4 |
| | Socialist Party of the Basque Country–Basque Country Left (PSE–EE (PSOE)) | 66,506 | 11.65 | –7.06 | 3 | –2 |
| | People's Party (PP) | 55,128 | 9.66 | –2.00 | 2 | –1 |
| | Citizens–Party of the Citizenry (C's) | 10,963 | 1.92 | New | 0 | ±0 |
| | Animalist Party Against Mistreatment of Animals (PACMA/ATTKAA) | 4,556 | 0.80 | +0.46 | 0 | ±0 |
| | Let's Win the Basque Country: Yes We Can (Ganemos Irabazi) | 3,337 | 0.58 | New | 0 | ±0 |
| | Zero Cuts–Green Group (Recortes Cero–GV) | 1,277 | 0.22 | New | 0 | ±0 |
| | Family and Life Party (PFyV) | 1,031 | 0.18 | +0.04 | 0 | ±0 |
| | Blank Seats (EB/AZ) | 903 | 0.16 | –0.76 | 0 | ±0 |
| | Basque Communists–Communist Party of the Peoples of Spain (EK–PCPE) | 466 | 0.08 | +0.01 | 0 | ±0 |
| | Humanist Party (PH) | 351 | 0.06 | –0.03 | 0 | ±0 |
| | Welcome (Ongi Etorri) | 250 | 0.04 | New | 0 | ±0 |
| Blank ballots | Blank ballots | 3,484 | 0.61 | –0.65 | | |
| Total | Total | 570,638 | | | 25 | ±0 |
| Valid votes | Valid votes | 570,638 | 99.56 | +0.33 | | |
| Invalid votes | Invalid votes | 2,495 | 0.44 | –0.33 | | |
| Votes cast / turnout | Votes cast / turnout | 573,133 | 60.48 | –3.99 | | |
| Abstentions | Abstentions | 374,503 | 39.52 | +3.99 | | |
| Registered voters | Registered voters | 947,636 | | | | |
| Sources |||||||
| Footnotes: $^1$ United We Can results are compared to the combined totals of United Left–The Greens: Plural Left and Equo Greens–Basque Ecologists in the 2012 election. |||||||

### 2012 regional election

Summary of the 21 October 2012 Basque Parliament election results in Biscay :
| Parties and alliances | Parties and alliances | Popular vote | Popular vote | Popular vote | Seats | Seats |
| Parties and alliances | Parties and alliances | Votes | % | ±pp | Total | +/- |
| | Basque Nationalist Party (EAJ/PNV) | 230,204 | 37.94 | –3.16 | 11 | –1 |
| | Basque Country Gather (EH Bildu)$^1$ | 128,644 | 21.20 | +14.11 | 6 | +5 |
| | Socialist Party of the Basque Country–Basque Country Left (PSE–EE (PSOE)) | 113,536 | 18.71 | –11.54 | 5 | –3 |
| | People's Party (PP) | 70,749 | 11.66 | –2.26 | 3 | –1 |
| | United Left–The Greens: Plural Left (IU–LV) | 16,109 | 2.65 | New | 0 | ±0 |
| | Union, Progress and Democracy (UPyD) | 10,855 | 1.79 | –0.07 | 0 | ±0 |
| | United Left–Greens (EB–B) | 9,817 | 1.62 | –1.79 | 0 | ±0 |
| | Blank Seats (EB/AZ) | 5,598 | 0.92 | New | 0 | ±0 |
| | Equo Greens–Basque Ecologists (Equo)$^2$ | 4,656 | 0.77 | +0.31 | 0 | ±0 |
| | Hartos.org (Hartos.org) | 2,831 | 0.47 | New | 0 | ±0 |
| | Animalist Party Against Mistreatment of Animals (PACMA/ATTKAA) | 2,052 | 0.34 | +0.08 | 0 | ±0 |
| | For a Fairer World (PUM+J) | 1,159 | 0.19 | –0.02 | 0 | ±0 |
| | Family and Life Party (PFyV) | 821 | 0.14 | –0.04 | 0 | ±0 |
| | Internationalist Socialist Workers' Party (POSI) | 778 | 0.13 | –0.03 | 0 | ±0 |
| | Humanist Party (PH) | 555 | 0.09 | +0.02 | 0 | ±0 |
| | Basque Communists–Communist Party of the Peoples of Spain (EK–PCPE) | 442 | 0.07 | New | 0 | ±0 |
| | Communist Unification of Spain (UCE) | 307 | 0.05 | New | 0 | ±0 |
| Blank ballots | Blank ballots | 7,649 | 1.26 | +0.24 | | |
| Total | Total | 606,762 | | | 25 | ±0 |
| Valid votes | Valid votes | 606,762 | 99.23 | +6.19 | | |
| Invalid votes | Invalid votes | 4,721 | 0.77 | –6.19 | | |
| Votes cast / turnout | Votes cast / turnout | 611,483 | 64.47 | –1.87 | | |
| Abstentions | Abstentions | 336,939 | 35.53 | +1.87 | | |
| Registered voters | Registered voters | 948,422 | | | | |
| Sources |||||||
| Footnotes: $^1$ Basque Country Gather results are compared to the combined totals of Aralar and Basque Solidarity in the 2009 election.$^2$ Equo Greens–Basque Ecologists results are compared to The Greens totals in the 2009 election. |||||||

### 2009 regional election

Summary of the 1 March 2009 Basque Parliament election results in Biscay :
| Parties and alliances | Parties and alliances | Popular vote | Popular vote | Popular vote | Seats | Seats |
| Parties and alliances | Parties and alliances | Votes | % | ±pp | Total | +/− |
| | Basque Nationalist Party (EAJ/PNV)$^1$ | 241,732 | 41.10 | n/a | 12 | +2 |
| | Socialist Party of the Basque Country–Basque Country Left (PSE–EE (PSOE)) | 177,875 | 30.25 | +7.05 | 8 | +2 |
| | People's Party (PP) | 81,837 | 13.92 | –3.55 | 4 | –1 |
| | Aralar (Aralar) | 24,639 | 4.19 | +2.63 | 1 | +1 |
| | United Left–Greens (EB–B) | 20,080 | 3.41 | –2.10 | 0 | –1 |
| | Basque Solidarity (EA)$^1$ | 17,033 | 2.90 | n/a | 0 | –1 |
| | Union, Progress and Democracy (UPyD) | 10,916 | 1.86 | New | 0 | ±0 |
| | The Greens (B/LV) | 2,689 | 0.46 | New | 0 | ±0 |
| | Anti-Bullfighting Party Against Mistreatment of Animals (PACMA/ZAAAA) | 1,504 | 0.26 | –0.02 | 0 | ±0 |
| | For a Fairer World (PUM+J) | 1,232 | 0.21 | +0.02 | 0 | ±0 |
| | Family and Life Party (PFyV) | 1,052 | 0.18 | New | 0 | ±0 |
| | Internationalist Socialist Workers' Party (POSI) | 969 | 0.16 | –0.07 | 0 | ±0 |
| | Humanist Party (PH) | 418 | 0.07 | –0.03 | 0 | ±0 |
| | Carlist Party of the Basque Country–Carlist Party (EKA–PC) | 151 | 0.03 | ±0.00 | 0 | ±0 |
| | Communist Party of the Basque Homelands (PCTV/EHAK) | n/a | n/a | –9.99 | 0 | –2 |
| Blank ballots | Blank ballots | 5,972 | 1.02 | +0.28 | | |
| Total | Total | 588,099 | | | 25 | ±0 |
| Valid votes | Valid votes | 588,099 | 93.04 | –6.63 | | |
| Invalid votes | Invalid votes | 43,971 | 6.96 | +6.63 | | |
| Votes cast / turnout | Votes cast / turnout | 632,070 | 66.34 | –1.57 | | |
| Abstentions | Abstentions | 320,774 | 33.66 | +1.57 | | |
| Registered voters | Registered voters | 952,844 | | | | |
| Sources |||||||
| Footnotes: $^1$ Within the Basque Nationalist Party–Basque Solidarity alliance in the 2005 election. |||||||

### 2005 regional election

Summary of the 17 April 2005 Basque Parliament election results in Biscay :
| Parties and alliances | Parties and alliances | Popular vote | Popular vote | Popular vote | Seats | Seats |
| Parties and alliances | Parties and alliances | Votes | % | ±pp | Total | +/− |
| | Basque Nationalist Party–Basque Solidarity (PNV–EA) | 267,247 | 40.66 | –2.76 | 11 | –1 |
| | Socialist Party of the Basque Country–Basque Country Left (PSE–EE (PSOE)) | 152,459 | 23.20 | +5.14 | 6 | +2 |
| | People's Party (PP) | 114,845 | 17.47 | –5.98 | 5 | –1 |
| | Communist Party of the Basque Homelands (PCTV/EHAK)$^1$ | 65,623 | 9.99 | +1.99 | 2 | ±0 |
| | United Left–Greens (EB–B)$^2$ | 36,226 | 5.51 | –0.14 | 1 | ±0 |
| | Aralar (Aralar) | 10,242 | 1.56 | New | 0 | ±0 |
| | Greens–Anti-Bullfighting Party Against Mistreatment of Animals (B–PACMA) | 1,865 | 0.28 | New | 0 | ±0 |
| | Internationalist Socialist Workers' Party (POSI) | 1,499 | 0.23 | New | 0 | ±0 |
| | For a Fairer World (PUM+J) | 1,261 | 0.19 | New | 0 | ±0 |
| | Humanist Party (PH) | 674 | 0.10 | –0.08 | 0 | ±0 |
| | Alavese Unity (UA) | 216 | 0.03 | New | 0 | ±0 |
| | Carlist Party of the Basque Country–Carlist Party (EKA–PC) | 179 | 0.03 | New | 0 | ±0 |
| Blank ballots | Blank ballots | 4,866 | 0.74 | –0.05 | | |
| Total | Total | 657,202 | | | 25 | ±0 |
| Valid votes | Valid votes | 657,202 | 99.67 | +0.08 | | |
| Invalid votes | Invalid votes | 2,164 | 0.33 | –0.08 | | |
| Votes cast / turnout | Votes cast / turnout | 659,366 | 67.91 | –11.21 | | |
| Abstentions | Abstentions | 311,591 | 32.09 | +11.21 | | |
| Registered voters | Registered voters | 970,957 | | | | |
| Sources |||||||
| Footnotes: $^1$ Communist Party of the Basque Homelands results are compared to Basque Citizens totals in the 2001 election.$^2$ United Left–Greens results are compared to United Left totals in the 2001 election. |||||||

### 2001 regional election

Summary of the 13 May 2001 Basque Parliament election results in Biscay :
| Parties and alliances | Parties and alliances | Popular vote | Popular vote | Popular vote | Seats | Seats |
| Parties and alliances | Parties and alliances | Votes | % | ±pp | Total | +/− |
| | Basque Nationalist Party–Basque Solidarity (PNV–EA)$^1$ | 335,945 | 43.42 | +4.85 | 12 | +2 |
| | People's Party (PP)$^2$ | 181,404 | 23.45 | +3.12 | 6 | +1 |
| | Socialist Party of the Basque Country–Basque Country Left (PSE–EE (PSOE)) | 139,684 | 18.06 | –0.21 | 4 | –1 |
| | Basque Citizens (EH) | 61,894 | 8.00 | –6.57 | 2 | –2 |
| | United Left (IU/EB) | 43,701 | 5.65 | –0.55 | 1 | ±0 |
| | Party of the Democratic Karma (PKD) | 2,000 | 0.26 | New | 0 | ±0 |
| | Humanist Party (PH) | 1,361 | 0.18 | –0.09 | 0 | ±0 |
| | Workers for Democracy Coalition (TD) | 1,017 | 0.13 | New | 0 | ±0 |
| | Freedom (Askatasuna) | 257 | 0.03 | New | 0 | ±0 |
| | Carlist Party (EKA/PC) | 220 | 0.03 | New | 0 | ±0 |
| Blank ballots | Blank ballots | 6,145 | 0.79 | –0.60 | | |
| Total | Total | 773,628 | | | 25 | ±0 |
| Valid votes | Valid votes | 773,628 | 99.59 | +0.16 | | |
| Invalid votes | Invalid votes | 3,180 | 0.41 | –0.16 | | |
| Votes cast / turnout | Votes cast / turnout | 776,808 | 79.12 | +15.59 | | |
| Abstentions | Abstentions | 204,995 | 20.88 | –15.59 | | |
| Registered voters | Registered voters | 981,803 | | | | |
| Sources |||||||
| Footnotes: $^1$ Basque Nationalist Party–Basque Solidarity results are compared to the combined totals of Basque Nationalist Party and Basque Solidarity in the 1998 election.$^2$ People's Party results are compared to the combined totals of the People's Party and Alavese Unity in the 1998 election. |||||||

### 1998 regional election

Summary of the 25 October 1998 Basque Parliament election results in Biscay :
| Parties and alliances | Parties and alliances | Popular vote | Popular vote | Popular vote | Seats | Seats |
| Parties and alliances | Parties and alliances | Votes | % | ±pp | Total | +/− |
| | Basque Nationalist Party (EAJ/PNV) | 224,542 | 32.60 | –2.51 | 9 | –1 |
| | People's Party (PP) | 139,161 | 20.20 | +5.17 | 5 | +1 |
| | Socialist Party of the Basque Country–Basque Country Left (PSE–EE (PSOE)) | 125,834 | 18.27 | +0.89 | 5 | +1 |
| | Basque Citizens (EH)$^1$ | 100,377 | 14.57 | +1.18 | 4 | +1 |
| | United Left (IU/EB) | 42,714 | 6.20 | –3.85 | 1 | –1 |
| | Basque Solidarity (EA) | 41,096 | 5.97 | –1.12 | 1 | –1 |
| | Natural Law Party (PLN/LNA) | 2,769 | 0.40 | New | 0 | ±0 |
| | Humanist Party (PH) | 1,892 | 0.27 | New | 0 | ±0 |
| | Alavese Unity (UA) | 913 | 0.13 | –0.13 | 0 | ±0 |
| Blank ballots | Blank ballots | 9,556 | 1.39 | –0.15 | | |
| Total | Total | 688,854 | | | 25 | ±0 |
| Valid votes | Valid votes | 688,854 | 99.43 | +0.03 | | |
| Invalid votes | Invalid votes | 3,972 | 0.57 | –0.03 | | |
| Votes cast / turnout | Votes cast / turnout | 692,781 | 63.53 | +3.16 | | |
| Abstentions | Abstentions | 298,457 | 36.47 | –3.16 | | |
| Registered voters | Registered voters | 991,238 | | | | |
| Sources |||||||
| Footnotes: $^1$ Basque Citizens results are compared to Popular Unity totals in the 1994 election. |||||||

### 1994 regional election

Summary of the 23 October 1994 Basque Parliament election results in Biscay :
| Parties and alliances | Parties and alliances | Popular vote | Popular vote | Popular vote | Seats | Seats |
| Parties and alliances | Parties and alliances | Votes | % | ±pp | Total | +/− |
| | Basque Nationalist Party (EAJ/PNV) | 201,833 | 35.11 | +0.74 | 10 | ±0 |
| | Socialist Party of the Basque Country–Basque Country Left (PSE–EE (PSOE))$^1$ | 99,931 | 17.38 | –9.86 | 4 | –3 |
| | People's Party (PP) | 86,398 | 15.03 | +6.41 | 4 | +2 |
| | Popular Unity (HB) | 76,988 | 13.39 | –2.83 | 3 | –1 |
| | United Left (IU/EB) | 57,765 | 10.05 | +8.34 | 2 | +2 |
| | Basque Solidarity (EA) | 40,752 | 7.09 | –0.91 | 2 | ±0 |
| | Alavese Unity (UA) | 1,489 | 0.26 | +0.23 | 0 | ±0 |
| | Coalition for a New Socialist Party (NPS)$^2$ | 804 | 0.14 | +0.08 | 0 | ±0 |
| Blank ballots | Blank ballots | 8,865 | 1.54 | +0.88 | | |
| Total | Total | 574,825 | | | 25 | ±0 |
| Valid votes | Valid votes | 574,825 | 99.40 | –0.08 | | |
| Invalid votes | Invalid votes | 3,496 | 0.60 | +0.08 | | |
| Votes cast / turnout | Votes cast / turnout | 578,321 | 60.37 | –0.16 | | |
| Abstentions | Abstentions | 379,691 | 39.63 | +0.16 | | |
| Registered voters | Registered voters | 958,012 | | | | |
| Sources |||||||
| Footnotes: $^1$ Socialist Party of the Basque Country–Basque Country Left results are compared to the combined totals of the Socialist Party of the Basque Country and Basque Country Left in the 1990 election.$^2$ Coalition for a New Socialist Party results are compared to Alliance for the Republic totals in the 1990 election. |||||||

### 1990 regional election

Summary of the 28 October 1990 Basque Parliament election results in Biscay :
| Parties and alliances | Parties and alliances | Popular vote | Popular vote | Popular vote | Seats | Seats |
| Parties and alliances | Parties and alliances | Votes | % | ±pp | Total | +/− |
| | Basque Nationalist Party (EAJ/PNV) | 192,903 | 34.37 | +5.56 | 10 | +2 |
| | Socialist Party of the Basque Country (PSE–PSOE) | 111,920 | 19.94 | –2.54 | 5 | –1 |
| | Popular Unity (HB) | 91,047 | 16.22 | +0.27 | 4 | ±0 |
| | People's Party (PP)$^1$ | 48,405 | 8.62 | +3.48 | 2 | +1 |
| | Basque Solidarity (EA) | 44,922 | 8.00 | –3.75 | 2 | –1 |
| | Basque Country Left (EE) | 40,983 | 7.30 | –2.91 | 2 | –1 |
| | United Left (IU/EB) | 9,609 | 1.71 | +0.92 | 0 | ±0 |
| | Socialist Democracy (DS) | 3,724 | 0.66 | New | 0 | ±0 |
| | Democratic and Social Centre (CDS) | 3,069 | 0.55 | –2.65 | 0 | ±0 |
| | The Ecologist Greens (LVE) | 2,447 | 0.44 | New | 0 | ±0 |
| | Basque Country Greens (EHB) | 2,415 | 0.43 | New | 0 | ±0 |
| | Ruiz-Mateos Group–European Democratic Alliance (ARM–ADE) | 2,070 | 0.37 | New | 0 | ±0 |
| | Workers' Socialist Party (PST) | 1,878 | 0.32 | +0.01 | 0 | ±0 |
| | Communist Party of the Basque Country People (PCPE/EHAC) | 599 | 0.11 | New | 0 | ±0 |
| | Humanist Party (PH) | 441 | 0.08 | –0.05 | 0 | ±0 |
| | Alliance for the Republic (AxR)$^2$ | 347 | 0.06 | –0.05 | 0 | ±0 |
| | Revolutionary Communist League–Communist Movement (LKI–EMK) | 326 | 0.06 | New | 0 | ±0 |
| | Communist Party of Spain (Marxist–Leninist) (PCE (m–l))$^3$ | 272 | 0.05 | –0.02 | 0 | ±0 |
| | Alavese Unity (UA) | 183 | 0.03 | New | 0 | ±0 |
| Blank ballots | Blank ballots | 3,679 | 0.66 | +0.22 | | |
| Total | Total | 561,239 | | | 25 | ±0 |
| Valid votes | Valid votes | 561,239 | 99.48 | –0.03 | | |
| Invalid votes | Invalid votes | 2,923 | 0.52 | +0.03 | | |
| Votes cast / turnout | Votes cast / turnout | 564,162 | 60.53 | –9.24 | | |
| Abstentions | Abstentions | 367,834 | 39.47 | +9.24 | | |
| Registered voters | Registered voters | 931,996 | | | | |
| Sources |||||||
| Footnotes: $^1$ People's Party results are compared to People's Alliance–Liberal Party totals in the 1986 election.$^2$ Alliance for the Republic results are compared to Internationalist Socialist Workers' Party totals in the 1986 election.$^3$ Communist Party of Spain (Marxist–Leninist) results are compared to Republican Popular Unity totals in the 1986 election. |||||||

### 1986 regional election

Summary of the 30 November 1986 Basque Parliament election results in Biscay :
| Parties and alliances | Parties and alliances | Popular vote | Popular vote | Popular vote | Seats | Seats |
| Parties and alliances | Parties and alliances | Votes | % | ±pp | Total | +/− |
| | Basque Nationalist Party (EAJ/PNV) | 183,766 | 28.81 | –14.94 | 8 | –4 |
| | Socialist Party of the Basque Country (PSE–PSOE) | 143,387 | 22.48 | –0.59 | 6 | ±0 |
| | Popular Unity (HB) | 101,733 | 15.95 | +3.02 | 4 | +1 |
| | Basque Solidarity (EA) | 74,921 | 11.75 | New | 3 | +3 |
| | Basque Country Left (EE) | 65,116 | 10.21 | +2.78 | 3 | +1 |
| | People's Alliance–Liberal Party (AP–PL)$^1$ | 32,764 | 5.14 | –4.25 | 1 | –1 |
| | Democratic and Social Centre (CDS) | 20,387 | 3.20 | New | 0 | ±0 |
| | United Left (IU/EB) | 5,055 | 0.79 | New | 0 | ±0 |
| | Communist Party of the Basque Country (PCE/EPK) | 3,895 | 0.61 | –1.16 | 0 | ±0 |
| | Workers' Socialist Party (PST) | 1,994 | 0.31 | –0.05 | 0 | ±0 |
| | Humanist Party (PH) | 856 | 0.13 | New | 0 | ±0 |
| | Internationalist Socialist Workers' Party (POSI) | 683 | 0.11 | New | 0 | ±0 |
| | Republican Popular Unity (UPR)$^2$ | 414 | 0.07 | –0.06 | 0 | ±0 |
| Blank ballots$^3$ | Blank ballots$^3$ | 2,798 | 0.44 | ±0.00 | | |
| Total | Total | 637,769 | | | 25 | ±0 |
| Valid votes | Valid votes | 637,769 | 99.51 | +0.05 | | |
| Invalid votes | Invalid votes | 3,169 | 0.49 | –0.05 | | |
| Votes cast / turnout | Votes cast / turnout | 640,938 | 69.77 | +1.51 | | |
| Abstentions | Abstentions | 277,747 | 30.23 | –1.51 | | |
| Registered voters | Registered voters | 918,685 | | | | |
| Sources |||||||
| Footnotes: $^1$ People's Alliance–Liberal Party results are compared to People's Coalition totals in the 1984 election.$^2$ Republican Popular Unity results are compared to Communist Party of Spain (Marxist–Leninist) totals in the 1984 election.$^3$ The 1983 electoral law provided that blank ballots would not count as valid votes for the application of the 5 percent threshold in each district. However, this rule was not determinant in excluding any party from seat distribution during its time of application (the 1984 and 1986 elections). As a result, and for comparison purposes, blank ballots are shown here included within valid votes. |||||||

### 1984 regional election

Summary of the 26 February 1984 Basque Parliament election results in Biscay :
| Parties and alliances | Parties and alliances | Popular vote | Popular vote | Popular vote | Seats | Seats |
| Parties and alliances | Parties and alliances | Votes | % | ±pp | Total | +/− |
| | Basque Nationalist Party (EAJ/PNV) | 261,911 | 43.75 | +3.78 | 12 | +3 |
| | Socialist Party of the Basque Country (PSE–PSOE) | 138,093 | 23.07 | +8.64 | 6 | +3 |
| | Popular Unity (HB) | 77,407 | 12.93 | –3.42 | 3 | –1 |
| | People's Coalition (AP–PDP–UL)$^1$ | 56,207 | 9.39 | +3.62 | 2 | +1 |
| | Basque Country Left (EE) | 44,500 | 7.43 | –0.35 | 2 | +1 |
| | Communist Party of the Basque Country (PCE/EPK) | 10,611 | 1.77 | –3.01 | 0 | –1 |
| | Neighborhood Labor (Auzolan)$^2$ | 4,357 | 0.73 | –0.88 | 0 | ±0 |
| | Workers' Socialist Party (PST) | 2,173 | 0.36 | –0.05 | 0 | ±0 |
| | Communist Party of Spain (Marxist–Leninist) (PCE (m–l)) | 792 | 0.13 | New | 0 | ±0 |
| | Union of the Democratic Centre (UCD) | n/a | n/a | –6.75 | 0 | –1 |
| Blank ballots$^3$ | Blank ballots$^3$ | 2,641 | 0.44 | +0.02 | | |
| Total | Total | 598,692 | | | 25 | +5 |
| Valid votes | Valid votes | 598,692 | 99.46 | +0.54 | | |
| Invalid votes | Invalid votes | 3,235 | 0.54 | –0.54 | | |
| Votes cast / turnout | Votes cast / turnout | 601,927 | 68.26 | +7.26 | | |
| Abstentions | Abstentions | 279,916 | 31.74 | –7.26 | | |
| Registered voters | Registered voters | 881,843 | | | | |
| Sources |||||||
| Footnotes: $^1$ People's Coalition results are compared to People's Alliance totals in the 1980 election.$^2$ Auzolan results are compared to the combined totals of Communist Movement of the Basque Country and Revolutionary Communist League in the 1980 election.$^3$ The 1983 electoral law provided that blank ballots would not count as valid votes for the application of the 5 percent threshold in each district. However, this rule was not determinant in excluding any party from seat distribution during its time of application (the 1984 and 1986 elections). As a result, and for comparison purposes, blank ballots are shown here included within valid votes. |||||||

### 1980 regional election

Summary of the 9 March 1980 Basque Parliament election results in Biscay :
| Parties and alliances | Parties and alliances | Popular vote | Popular vote | Popular vote | Seats | Seats |
| Parties and alliances | Parties and alliances | Votes | % | ±pp | Total | +/− |
| | Basque Nationalist Party (EAJ/PNV) | 206,051 | 39.97 | n/a | 9 | n/a |
| | People's Unity (HB) | 84,273 | 16.35 | n/a | 4 | n/a |
| | Socialist Party of the Basque Country (PSE–PSOE) | 74,379 | 14.43 | n/a | 3 | n/a |
| | Basque Country Left (EE) | 40,085 | 7.78 | n/a | 1 | n/a |
| | Union of the Democratic Centre (UCD) | 34,781 | 6.75 | n/a | 1 | n/a |
| | People's Alliance (AP) | 29,747 | 5.77 | n/a | 1 | n/a |
| | Communist Party of the Basque Country (PCE/EPK) | 24,660 | 4.78 | n/a | 1 | n/a |
| | Communist Movement of the Basque Country (EMK/MCE) | 5,654 | 1.10 | n/a | 0 | n/a |
| | Spanish Socialist Workers' Party (historical) (PSOEh) | 2,760 | 0.54 | n/a | 0 | n/a |
| | Revolutionary Communist League (LKI/LCR) | 2,652 | 0.51 | n/a | 0 | n/a |
| | Workers' Socialist Party (PST) | 2,099 | 0.41 | n/a | 0 | n/a |
| | Spanish Phalanx of the CNSO (FE–JONS) | 1,466 | 0.28 | n/a | 0 | n/a |
| | Workers' Party of the Basque Country (ORT–PTE) | 1,404 | 0.27 | n/a | 0 | n/a |
| | Basque Socialists' Unity Force (ESEI) | 1,343 | 0.26 | n/a | 0 | n/a |
| | Communist Unity (UC) | 1,340 | 0.26 | n/a | 0 | n/a |
| | Carlist Party (EKA/PC) | 684 | 0.13 | n/a | 0 | n/a |
| Blank ballots | Blank ballots | 2,164 | 0.42 | n/a | | |
| Total | Total | 515,542 | | | 20 | n/a |
| Valid votes | Valid votes | 515,542 | 98.92 | n/a | | |
| Invalid votes | Invalid votes | 5,652 | 1.08 | n/a | | |
| Votes cast / turnout | Votes cast / turnout | 521,194 | 61.00 | n/a | | |
| Abstentions | Abstentions | 333,173 | 39.00 | n/a | | |
| Registered voters | Registered voters | 854,367 | | | | |
| Sources |||||||