The decision to uphold the 2008 Net Worth Tax adopted by Gipuzkoa Provincial Council, making the province the only one in the Spanish State where that tax concept remained in force, led to a barrage of appeals, arguing the unconstitutionality of that decision as it breached the principle of equality, as well as the principles contained in Article 3 of the Basque Economic Agreement relating to the general fiscal structure and the coordination and harmonisation rules.
Those appeals were then fully dismissed by the Administrative Litigation Chamber of the High Court of the Basque Country. However, its rulings were overturned by the Constitutional Court as it found for the petitions for constitutional protection lodged against them, as it ruled that the right to the effective judicial protection of the petitioners had been breached, a constitutional principle contained in Article 24 of that legal text, as it could not find sufficient grounds for the Court of First Instance to hear the unconstitutionality issue.
After the procedures had been sent back to the High Court of Justice, the Administrative Litigation Chamber has again ruled in the same way as initially. However, it has had to make its case for not finding for the aforementioned breach of the principle of equality and of the general principles contained in Article 3 of the Economic Agreement.
For further details, see the Ruling of the Constitutional Court No. 239/2015, of 30 November, and those of the High Court of Justice of the Basque Country of 16 July 2012 and of 24 February 2016.