This was to be provided by the Socialist Party of the Basque Country–Basque Country Left (PSE–EE), which despite scoring the worst result in its history after seeing its support almost halved—falling from 18.9% and 16 seats to 11.9% and 9 seats—would go on to form a coalition minority government with the PNV.

EH Bildu was able to hold onto second place, albeit with a reduced support by going down from 21 to 17 seats, whereas the Elkarrekin Podemos alliance scored third, but below campaign expectations.

[6] The resulting coalition recovered an alliance which both the PNV and the PSE had already formed between 1987 and 1998 in the Basque government,[7][8] and which had already been extended to city councils and the Juntas Generales following the 2015 local and foral elections.

[18] Voting for the Parliament was on the basis of universal suffrage, which comprised all nationals over 18 years of age, registered in the Basque Country and in full enjoyment of their political rights.

[19] The 75 members of the Basque Parliament were elected using the D'Hondt method and a closed list proportional representation, with an electoral threshold of three percent of valid votes—which included blank ballots—being applied in each constituency.

[21] The Basque Parliament was officially dissolved on 2 August 2016 after the publication of the dissolution decree in the BOPV, setting the election date for 25 September.

[23] The agreement eventually led to the culmination of an ideological realignment within the PNV, whose economic stance had been swinging in the previous years towards social democracy in detriment of its traditional pro-liberal positions.

[24] Additionally, the PNV under Urkullu had abandoned the confrontational style of former lehendakari Juan José Ibarretxe as well as his sovereigntist plan, moving towards more moderate, pragmatic and big tent positions.

[55] Despite this, on 24 May the EH Bildu coalition proclaimed him as its leading candidate for lehendakari, on grounds that the ruling did not specify what specific criminal charges affected his disqualification.

[59] On 24 August the provincial electoral commission of Gipuzkoa ruled that Otegi could not be a candidate in the lists of EH Bildu for being barred to stand for election as part of his sentence.

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