There was "a political earthquake" in Spain this week, as the relationship between the conservative Partido Popular (PP) party and liberal Ciudadanos (Cs) took a turn for the worse.
The PP had been in coalition with Cs in several regional governments, however, on Wednesday, Cs formally broke with its PP coalition in the Murcia region and combined with opposition parties there to table a no-confidence vote in the ruling regional PP.
Both PP and Cs did badly in the recent election in Catalonia. While reports say that the PP's national leader, Pablo Casado, aspired to merging Cs into his party, and so reuniting the centre-right, the national leader of Cs, Inés Arrimadas, is said to want to distance herself from the PP in an effort to shore up the declining support for her party.
As a result of the announcement of the Murcia no-confidence motion, the president of the Madrid region, the PP's Isabel Díaz Ayuso, fearing her own Cs-supported government was next, immediately dissolved the regional assembly and called elections for 4 May.
Rules say if elections are planned, a no-confidence vote cannot be called. But there was confusion as to whether the call to elections was valid from Ayuso's announcement on Wednesday or the official dissolution of the regional assembly on Thursday.
To be on the safe side, by Wednesday evening, both the Socialist PSOE and the Más Madrid parties had lodged separate no- confidence motions in the PP's Madrid leadership, and on Thursday said they would challenge Ayuso's dissolution in court.
Ayuso's vice-president, Ignacio Aguado (Cs), was angry with the regional president's decision to dissolve the Madrid assembly. He said the decision was "a personal whim, probably pushed for by her entourage".
To add to Wednesday's drama, the Socialist party in the Castilla y León region also presented a no-confidence motion against the PP there, however the PP's coalition with Cs was expected to hold firm.
Observers said that the emerging PP and Cs split would force the PP to look more to far-right Vox for support, despite the PP leader recently trying to distance himself from Vox and its policies.