Biscay (, ) is one of the three constituencies () 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 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 () 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 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

Regional elections 2024 + Summary of the 21 April 2024 Basque Parliament election results in Biscay Parties and alliances Popular vote Seats 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 5,528 0.96 +0.01 Total 570,994 25 ±0 Valid votes 570,994 99.24 +0.06 Invalid votes 4,371 0.76 –0.06 Votes cast / turnout 575,365 60.83 +10.43 Abstentions 370,513 39.17 –10.43 Registered voters 945,878 Sources

2020 + Summary of the 12 July 2020 Basque Parliament election results in Biscay Parties and alliances Popular vote Seats 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 4,524 0.95 +0.34 Total 475,142 25 ±0 Valid votes 475,142 99.18 –0.38 Invalid votes 3,916 0.82 +0.38 Votes cast / turnout 479,058 50.40 –10.08 Abstentions 471,506 49.60 +10.08 Registered voters 950,564 Sources

2016 + Summary of the 25 September 2016 Basque Parliament election results in Biscay Parties and alliances Popular vote Seats 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 3,484 0.61 –0.65 Total 570,638 25 ±0 Valid votes 570,638 99.56 +0.33 Invalid votes 2,495 0.44 –0.33 Votes cast / turnout 573,133 60.48 –3.99 Abstentions 374,503 39.52 +3.99 Registered voters 947,636 Sources

2012 + Summary of the 21 October 2012 Basque Parliament election results in Biscay Parties and alliances Popular vote Seats 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 7,649 1.26 +0.24 Total 606,762 25 ±0 Valid votes 606,762 99.23 +6.19 Invalid votes 4,721 0.77 –6.19 Votes cast / turnout 611,483 64.47 –1.87 Abstentions 336,939 35.53 +1.87 Registered voters 948,422 Sources

2009 + Summary of the 1 March 2009 Basque Parliament election results in Biscay Parties and alliances Popular vote Seats 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 5,972 1.02 +0.28 Total 588,099 25 ±0 Valid votes 588,099 93.04 –6.63 Invalid votes 43,971 6.96 +6.63 Votes cast / turnout 632,070 66.34 –1.57 Abstentions 320,774 33.66 +1.57 Registered voters 952,844 Sources

2005 + Summary of the 17 April 2005 Basque Parliament election results in Biscay Parties and alliances Popular vote Seats 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 4,866 0.74 –0.05 Total 657,202 25 ±0 Valid votes 657,202 99.67 +0.08 Invalid votes 2,164 0.33 –0.08 Votes cast / turnout 659,366 67.91 –11.21 Abstentions 311,591 32.09 +11.21 Registered voters 970,957 Sources

2001 + Summary of the 13 May 2001 Basque Parliament election results in Biscay Parties and alliances Popular vote Seats 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 6,145 0.79 –0.60 Total 773,628 25 ±0 Valid votes 773,628 99.59 +0.16 Invalid votes 3,180 0.41 –0.16 Votes cast / turnout 776,808 79.12 +15.59 Abstentions 204,995 20.88 –15.59 Registered voters 981,803 Sources

1998