Juan García-Gallardo, Vox's vice president in Castilla y León, has officially announced his resignation, marking the end of the party's coalition with the Popular Party (PP) in the region.
This decision comes after Vox's national leadership, led by Santiago Abascal, called for breaking all regional government agreements with PP.
The main catalyst for this rupture was PP's agreement to accept unaccompanied migrant minors, which Vox strongly opposes.
García-Gallardo cited this as 'the last straw' in their disagreements.
Despite the split, Castilla y León's President Alfonso Fernández Mañueco has called for calm and ruled out early elections.
The breakup ends a two-year coalition that Abascal once described as a 'pilot project' between the two parties.