The founder of Vox, Santiago Abascal, said this week that his party was "growing thanks to the insults" of other political parties. That in part explains the stunning increase in support for his party, qualified by some as far-right and by others as just right wing. France's far-right leader Marie Le Pen congratulated Vox on its achievement in Andalucía after Sunday's vote.
The regional leader, Francisco Serrano, is a judge from Seville well known for a tough stance in favour of fathers in domestic cases. Without any opinion poll predicting it, he managed to secure 11 per cent of the vote in last weekend's election.
With the 12 seats of Serrano holding the key, the right-wing parties have a majority to remove the PSOE from power for the first time. Abascal said this week that he was prepared to work with either the PP or Ciudadanos party regardless. He said that he had no wish to form part of the regional government but has laid down conditions for his members' support in an investiture vote.
One of these would be the closure of the regional broadcasting company RTVA, which has nearly 1,500 employees and runs the TV station Canal Sur.
Vox's policies include the abolition of regional autonomies and a return to a centralised state. They want to repeal gender equality legislation, criticising the strength of the feminist movement, and repeal 'historical memory' laws that seek to investigate events under Franco's regime. They are conservative on abortion and pro-family. Some of Vox's more radical ideas have been filtered out of its manifesto since it was founded in early 2014. Other than a few councillors, until last Sunday, it has never had serious political representation.
While left-wing parties and many members of the public called for protests and a fight back, claiming the party are "fachas" or fascists, analysts have been rushing to explain where the support came from last Sunday.
Most point to Spain catching up with many other countries in having a home-grown version of far-right populism. They agree that its rise is down to discontent with the traditional parties, that have been mired in corruption scandals in recent years.
Immigration has played a part, say some. Vox wants to expel illegal immigrants from Spain and build a stronger barrier in Spain's North African towns of Ceuta and Melilla. The highest vote for Vox last Sunday was 30 per cent in the town of El Ejido, Almería, with a high immigrant population working in the fruit industry.
A reaction to Catalan separatism has also been cited by observers, where many feel the PSOE government nationally has been too generous to those involved in the illegal independence movement. Analysis shows that moderate votes from both the left and right wing have been attracted for this reason.