In the run up to the 2023 Spanish local elections, various organisations carried out opinion polling to gauge voting intention in local entities in Spain. Results of such polls for municipalities and the three foral deputations (General Assemblies) in the Basque Country are displayed in this article. The date range for these opinion polls is from the previous local elections, held on 26 May 2019, to the day the next elections were held, on 28 May 2023.

Polls are listed 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" columns on the right shows the percentage-point difference between the parties with the highest percentages in a given poll.

Municipalities

Barakaldo Polling firm/Commissioner Fieldwork date Sample size Turnout Lead 2023 municipal election 28 May 2023 56.0 36.0 24.5 8.7 15.9 7.2 – 2.9 11.5 Gizaker/EiTB 26 Apr–12 May 2023 400 61.0 42.1 24.9 10.8 13.6 5.2 – – 17.2 Gizaker/EiTB 27 Feb–17 Mar 2023 400 59.0 40.8 26.2 9.7 13.2 5.4 – 2.7 14.6 Gizaker/Inguralde 12–16 Dec 2022 700 61.0 39.0 26.2 13.1 12.6 6.2 1.1 0.9 12.8 2019 municipal election 26 May 2019 62.5 38.6 27.0 13.2 11.5 5.7 1.5 1.1 11.6

Basauri Polling firm/Commissioner Fieldwork date Sample size Turnout Lead 2023 municipal election 28 May 2023 55.7 39.3 22.6 19.6 8.1 7.5 – 16.7 Gizaker/EiTB 26 Apr–12 May 2023 400 62.0 45.0 21.8 16.4 8.5 5.0 – 23.2 Gizaker/EiTB 27 Feb–17 Mar 2023 400 63.0 45.7 21.5 15.1 9.3 5.0 – 24.2 2019 municipal election 26 May 2019 62.9 43.1 22.7 13.3 10.7 5.4 0.8 20.4

Bilbao

Polling firm/Commissioner Fieldwork date Sample size Turnout Lead 2023 municipal election 28 May 2023 56.2 36.6 16.4 18.9 8.0 12.1 0.2 3.4 – 17.7 Sigma Dos/EiTB 25–28 May 2023 700? 42.4 16.3 17.5 9.7 10.2 – – – 24.9 NC Report/La Razón 22 May 2023?? 42.9 14.9 16.2 7.9 10.9 – – – 26.7 Gizaker/EiTB 26 Apr–12 May 2023 400 60.0 45.2 15.5 17.3 7.1 9.4 – 2.5 – 27.9 Ikerfel/El Correo 25 Apr–12 May 2023?? 43.9 15.8 16.8 10.3 8.6 – 1.8 – 27.1 Ikerfel/GPS 2–5 May 2023? 59.5 44.3 15.5 16.0 8.0 8.9 – 2.9 – 28.3 CIS 10–26 Apr 2023 601? 36.4 17.0 19.7 9.9 9.2 0.7 4.1 – 16.7 NC Report/La Razón 24 Apr 2023? 62.8 41.1 15.6 15.5 9.5 11.3 – – – 25.5 EM-Analytics/Crónica Vasca 19 Sep–4 Apr 2023 1,501? 43.8 15.3 15.8 9.9 10.3 1.2 2.1 - 28.0 Gizaker/EiTB 27 Feb–17 Mar 2023 400 60.0 44.0 14.7 17.1 9.9 7.9 – 3.2 – 26.9 Sigma Dos/El Mundo 3–8 Mar 2023 629? 41.6 16.9 15.5 9.7 9.2 – – – 24.7 Ikerfel/GPS 31 Jan–6 Feb 2023? 58.5 45.7 15.9 14.7 7.9 8.8 – 2.2 – 29.8 Ikerfel/GPS 3–7 Oct 2022? 59.0 44.3 15.2 16.4 8.5 8.7 – 2.0 – 27.9 EM-Analytics/Crónica Vasca 10 May–18 Sep 2022 1,008? 40.2 15.7 15.5 11.0 2.0 12.1 24.5 Ikerfel/GPS 6–10 Jun 2022 443 58.5 44.7 15.9 15.4 8.8 9.0 – 2.7 – 28.8 EM-Analytics/Crónica Vasca 2–19 May 2022 757? 40.8 15.7 15.2 10.7 1.9 12.3 25.1 Gizaker/EiTB 5–12 May 2022 400? 46.7 15.0 14.9 9.5 8.0 0.5 3.0 – 31.7 Gizaker/City Council of Bilbao 19–26 May 2021 1,000 61.0 43.0 15.7 17.1 8.8 9.5 – 2.7 – 25.9 2019 municipal election 26 May 2019 61.8 42.7 15.9 14.9 10.5 9.2 2.2 1.1 – 26.8

Donostia-San Sebastián

Polling firm/Commissioner Fieldwork date Sample size Turnout Lead 2023 municipal election 28 May 2023 59.9 27.9 26.7 18.6 12.1 8.1 0.2 2.4 1.2 Sigma Dos/EiTB 25–28 May 2023 700? 33.0 27.5 16.8 8.8 9.8 – – 5.5 Gizaker/EiTB 26 Apr–12 May 2023 400 63.0 32.9 25.2 17.7 10.4 9.2 – 1.5 7.7 Ikerfel/Diario Vasco 25 Apr–12 May 2023 400 60.3 32.3 26.4 18.1 10.6 9.6 – 1.7 5.9 Ikerfel/GPS 2–5 May 2023? 61.0 33.9 25.2 16.5 9.5 8.4 – 2.5 8.7 Gizaker/EiTB 27 Feb–17 Mar 2023 400 64.0 36.3 24.1 17.4 9.1 9.7 – 0.8 12.2 Ikerfel/GPS 31 Jan–6 Feb 2023? 60.5 34.3 24.3 17.6 9.7 8.1 – 2.2 10.0 Ikerfel/GPS 3–7 Oct 2022? 59.5 33.8 21.7 21.5 9.4 7.9 – 2.2 12.1 Ikerfel/GPS 6–10 Jun 2022 400 59.0 37.1 22.7 17.2 9.2 7.9 – 2.1 14.4 Gizaker/EiTB 5–12 May 2022 400? 37.3 24.7 16.5 8.6 8.0 1.0 1.8 12.6 ElectoPanel/Electomanía 1 Apr–15 Jun 2020?? 30.4 24.9 20.1 12.1 7.5 – – 5.5 2019 municipal election 26 May 2019 65.3 35.5 21.2 17.5 10.8 9.9 1.6 1.3 14.3

Durango Polling firm/Commissioner Fieldwork date Sample size Turnout HE Lead 2023 municipal election 28 May 2023 64.1 35.4 37.8 4.5 8.2 6.1 6.6 2.4 Aztiker/City Council of Durango 16–27 Jan 2023 614 64.6 36.7 33.0 12.1 9.4 5.0 – 3.7 2019 municipal election 26 May 2019 68.2 35.3 32.3 16.3 10.0 4.5 – 3.0

Eibar Polling firm/Commissioner Fieldwork date Sample size Turnout Lead 2023 municipal election 28 May 2023 60.3 36.4 25.7 26.8 5.4 3.9 9.6 Gizaker/EiTB 26 Apr–12 May 2023 400 63.0 35.9 28.6 27.3 4.1 3.5 7.3 Gizaker/EiTB 27 Feb–17 Mar 2023 400 65.0 35.3 28.7 24.9 6.2 4.0 6.6 2019 municipal election 26 May 2019 67.5 39.2 25.9 24.0 6.6 3.5 13.3

Getxo Polling firm/Commissioner Fieldwork date Sample size Turnout Lead 2023 municipal election 28 May 2023 62.3 31.7 21.7 20.2 10.3 5.6 – 3.4 10.0 Gizaker/EiTB 26 Apr–12 May 2023 400 62.0 40.2 15.8 20.1 9.2 7.4 – 2.7 20.1 Gizaker/EiTB 27 Feb–17 Mar 2023 400 65.0 38.6 14.1 18.2 10.9 7.7 – 4.2 20.4 2019 municipal election 26 May 2019 67.5 39.1 16.4 15.1 10.6 8.0 3.2 1.6 22.7

Irun Polling firm/Commissioner Fieldwork date Sample size Turnout Lead 2023 municipal election 28 May 2023 54.1 32.7 23.0 9.2 16.1 8.5 – 4.1 9.7 Gizaker/EiTB 26 Apr–12 May 2023 400 61.0 32.7 26.6 13.3 19.3 6.3 – – 6.1 Ikerfel/Diario Vasco 25 Apr–12 May 2023 400 59.0 32.4 26.1 14.7 16.1 6.3 – 2.6 6.3 Gizaker/EiTB 27 Feb–17 Mar 2023 400 60.0 31.9 28.3 12.0 18.6 6.7 – 1.7 3.6 2019 municipal election 26 May 2019 60.8 35.7 24.8 15.4 13.8 5.5 2.3 1.6 10.9

Llodio Polling firm/Commissioner Fieldwork date Sample size Turnout Omnia Lead 2023 municipal election 28 May 2023 63.5 33.8 34.1 15.1 9.6 – 4.2 1.6 0.3 Gizaker/EiTB 26 Apr–12 May 2023 400 64.0 33.9 31.3 16.5 9.3 4.7 3.4 – 2.6 Gizaker/EiTB 27 Feb–17 Mar 2023 400 66.0 33.2 27.8 18.4 10.1 3.9 4.5 – 5.4 2019 municipal election 26 May 2019 67.8 36.2 24.7 18.2 10.4 4.7 4.4 0.7 11.5

Salvatierra-Agurain Polling firm/Commissioner Fieldwork date Sample size Turnout Lead 2023 municipal election 28 May 2023 66.2 46.2 48.6 3.1 0.9 – – 2.4 Gizaker/EiTB 26 Apr–12 May 2023 200 68.0 42.9 46.7 5.2 3.0 – – 3.8 Gizaker/EiTB 27 Feb–17 Mar 2023 200 69.0 45.5 45.8 3.6 2.6 1.1 1.4 0.3 2019 municipal election 26 May 2019 67.5 45.6 44.9 4.4 3.2 1.0 – 0.7

Tolosa Polling firm/Commissioner Fieldwork date Sample size Turnout Lead 2023 municipal election 28 May 2023 63.3 36.6 49.2 7.5 3.1 1.9 12.6 Gizaker/EiTB 26 Apr–12 May 2023 400 64.0 39.5 48.6 6.1 3.9 1.2 9.1 Gizaker/EiTB 27 Feb–17 Mar 2023 400 70.0 41.3 42.7 8.2 4.7 1.8 1.4 2019 municipal election 26 May 2019 68.8 43.4 41.3 7.2 5.2 2.1 2.1

Vitoria-Gasteiz

Polling firm/Commissioner Fieldwork date Sample size Turnout Lead 2023 municipal election 28 May 2023 58.1 19.7 21.9 22.8 20.1 7.1 0.2 3.8 0.9 Sigma Dos/EiTB 25–28 May 2023 700? 23.7 22.2 24.4 19.4 6.7 – – 0.7 Gizaker/EiTB 26 Apr–12 May 2023 400 61.0 25.2 19.4 23.9 19.1 7.8 – 2.1 1.3 Ikerfel/El Correo 25 Apr–12 May 2023?? 22.5 22.2 20.3 19.5 10.8 – 2.3 0.3 Ikerfel/GPS 2–5 May 2023? 60.0 23.8 21.2 22.7 18.5 7.3 – 3.2 1.1 Gizaker/City Council of Vitoria 23–24 Mar 2023 1,150?????? – –? Gizaker/EiTB 27 Feb–17 Mar 2023 400 61.0 25.6 19.2 22.3 18.3 10.0 – 2.8 3.3 PP 14 Mar 2023??????? – –? Ikerfel/GPS 31 Jan–6 Feb 2023? 60.0 24.3 20.9 21.6 18.1 6.8 – 4.0 2.7 EM-Analytics/Crónica Vasca 8 Dec–4 Feb 2023 1,647? 25.8 22.5 23.6 17.0 6.1 0.8 3.8 2.2 Gizaker/Grupo Noticias 13–16 Dec 2022 800? 26.6 19.4 22.5???? 4.1 EM-Analytics/Crónica Vasca 16 Jul–7 Dec 2022 1,257? 25.6 22.8 23.4 16.9 6.1 1.0 4.1 2.2 Ikerfel/GPS 3–7 Oct 2022? 60.0 24.2 21.5 21.3 18.2 7.1 – 3.4 2.7 EM-Analytics/Crónica Vasca 2–15 Jun 2022 770? 25.5 22.3 22.8? 6.8 1.0 3.9 2.7 Ikerfel/GPS 6–10 Jun 2022 601 59.5 24.3 20.4 22.0 18.0 7.3 – 4.6 2.3 Gizaker/EiTB 5–12 May 2022 400? 24.5 21.0 22.6 17.7 8.0 1.3 3.9 1.9 EM-Analytics/Electomanía 13 May-8 Oct 2021 361? 24.9 22.0 22.1 16.4 7.7 1.1 3.6 2.8 Gizaker/City Council of Vitoria 7-11 Jun 2021 1,150?????? – –? 2019 municipal election 26 May 2019 63.3 23.6 21.4 20.1 18.5 9.9 2.5 1.4 3.1

General Assemblies Álava Polling firm/Commissioner Fieldwork date Sample size Turnout Lead 2023 foral election 28 May 2023 59.6 25.9 25.1 18.4 17.0 7.0 – 3.0 – 0.8 Gizaker/EiTB 26 Apr–12 May 2023 1,543 61.9 30.8 24.4 16.6 15.4 8.8 – 1.7 – 6.4 Ikerfel/El Correo 25 Apr–12 May 2023 2,850 68.3 31.1 21.0 19.1 15.3 9.2 – 2.7 – 10.1 Ikerfel/GPS 2–5 May 2023 728 60.5 31.0 22.2 18.2 15.4 7.1 – 3.0 – 8.8 Aztiker/Gara 11–25 Apr 2023 500? 28.5 22.5 18.1 14.4 7.8 – 5.1 – 6.0 Gizaker/EiTB 27 Feb–17 Mar 2023 1,543 62.5 31.7 23.6 18.0 13.8 8.6 – 2.4 – 8.1 Ikerfel/Álava Deputation 26 Feb–15 Mar 2023 1,200 57.7 31.3 24.2 17.2 13.9 7.4 – 2.9 – 7.1 Aztiker/Gara 14–25 Feb 2023 500? 28.8 22.2 18.1 14.2 7.5 – 5.1 – 6.6 Ikerfel/GPS 31 Jan–6 Feb 2023 728 58.5 31.5 22.8 18.0 15.0 6.6 – 3.1 – 8.7 Ikerfel/GPS 13–20 Oct 2022 1,204 55.2 31.5 23.1 18.0 15.1 7.8 – 2.4 – 8.4 Ikerfel/GPS 3–7 Oct 2022 800 59.5 30.5 23.2 18.8 14.0 6.7 – 3.0 – 7.3 Ikerfel/GPS 6–10 Jun 2022 800 58.5 31.6 23.3 17.0 14.0 6.8 – 3.4 – 8.3 Gizaker/EiTB 5–12 May 2022 550? 32.0 23.0 18.1 14.2 7.3 0.6 2.8 – 9.0 2020 regional election 12 Jul 2020 49.0 31.9 24.6 15.5 8.0 3.8 11.4 7.3 November 2019 general election 10 Nov 2019 66.6 23.6 16.1 21.9 14.9 16.5 1.5 3.8 – 2.7 2019 foral election 26 May 2019 65.3 29.4 21.0 18.9 15.0 9.9 2.3 1.4 – 8.4

Biscay Polling firm/Commissioner Fieldwork date Sample size Turnout Lead 2023 foral election 28 May 2023 60.1 38.4 25.0 15.9 7.3 8.2 – 2.0 – 13.4 Gizaker/EiTB 26 Apr–12 May 2023 2,483 61.8 44.3 21.8 15.9 8.4 6.7 – 1.8 – 22.5 Ikerfel/El Correo 25 Apr–12 May 2023 2,850 63.9 43.4 21.1 17.1 8.9 7.0 – 1.1 – 22.3 Ikerfel/GPS 2–5 May 2023 1,318 62.5 44.2 22.0 15.4 7.0 6.8 – 1.7 – 22.2 Gizaker/Biscay Deputation 17–25 Apr 2023 3,000 65.1 43.4 22.1 15.3 9.8 6.2 – 2.0 – 21.3 Aztiker/Gara 11–25 Apr 2023 500? 42.4 21.5 16.1 8.4 6.5 – 2.6 – 20.9 Gizaker/EiTB 27 Feb–17 Mar 2023 2,483 66.7 45.4 22.6 15.3 8.4 5.2 – 1.9 – 22.8 Aztiker/Gara 14–25 Feb 2023 500? 42.9 21.3 16.1 8.1 6.4 – 2.5 – 21.6 Ikerfel/GPS 31 Jan–6 Feb 2023 1,318 59.5 44.6 22.2 15.7 7.3 7.2 – 1.4 – 22.4 Ikerfel/GPS 3–7 Oct 2022 1,449 60.5 44.4 22.4 14.4 8.2 7.1 – 1.2 – 22.0 Gizaker/Biscay Deputation 8–22 Jun 2022 3,000 64.7 44.5 21.5 15.3 8.9 6.5 1.0 1.5 – 23.0 Ikerfel/GPS 6–10 Jun 2022 1,449 59.5 44.6 22.3 14.7 7.8 7.3 – 1.7 – 22.3 Gizaker/EiTB 5–12 May 2022 600? 45.7 22.2 15.1 7.6 6.6 0.8 1.5 – 23.5 Ikerfel/Biscay Deputation 8–29 Dec 2021 2,503 55.4 44.6 21.9 14.8 8.3 6.6 0.8 1.9 – 22.7 Gizaker/Biscay Deputation 16–30 Jun 2021 3,000 60.7 45.5 21.0 15.0 9.1 6.4 1.1 1.0 – 24.5 2020 regional election 12 Jul 2020 50.4 42.2 23.7 13.5 8.5 1.9 6.8 18.5 November 2019 general election 10 Nov 2019 66.8 35.2 15.0 19.1 15.4 8.8 1.1 2.4 – 16.1 2019 foral election 26 May 2019 65.7 43.1 19.7 16.5 10.5 6.6 1.2 0.9 – 23.4

Gipuzkoa