Photo by Lluis Gene, AFP

Catalonia’s regional government on Monday voted in favor of a resolution to split from Spain, launching a so-called roadmap towards independence which the central government in Madrid has vowed to block, Reuters reports.

The declaration on secession, the first step which pro-independence parties hope will lead to the northeastern region splitting from Spain within 18 months, was backed by a majority in the regional parliament.

Parties favoring independence from Spain won a majority of seats in the Catalan regional election in September. The Spanish constitution does not allow any region to break away, however, and the center-right government of Spanish premier Mariano Rajoy, facing a general election in December, has said it will immediately seek to block the resolution in the courts.