Separatist parties and the left-wing, anti-independence En Comu Podem (“Together we Can”) party joined forces to vote for the resolution which condemned the monarch's “intervention in the Catalan conflict” and called for “the abolition of an outdated and undemocratic institution like the monarchy.”
Felipe VI is a divisive figure in the northeastern region since he made a stern speech in October 2017 denouncing the secession attempt by Catalan leaders.
Sanchez has until now trodden carefully as he negotiates with Catalan president Quim Torra in a bid to ease the situation in the region where roughly half of the population supports independence.
But on Thursday, he tweeted that “the resolution voted this afternoon in Catalonia's parliament that wants to reject and condemn the head of state is unacceptable.”
Es inadmisible la resolución votada esta tarde en el Parlament de Cataluña que pretende rechazar y condenar al jefe del Estado. Este #Gobierno adoptará las medidas legales a su alcance en defensa de la legalidad, la Constitución y las instituciones del Estado.
— Pedro Sánchez (@sanchezcastejon) October 11, 2018
“This government will adopt the legal measures at its disposal to defend the law, the constitution and state institutions,” he added, without specifying what the measures would be.
In a statement, the Spanish government added that the resolution was “a product of the loss of direction of separatist groups which, inexplicably, got the support of another parliamentary group.”
It blasted them for “using Catalan institutions to encourage the conflict and not to serve the general interest of all Catalans.”
Without En Comu Podem, however, Catalonia's separatist government is in minority in the regional parliament due to a rift between two major pro-independence parties, casting doubt over the executive's viability.
This is a major change from December 2017, when separatist parties got an absolute majority in snap regional elections called by then prime minister Mariano Rajoy after the failed secession bid in October.