Spain's prime minister has asked the country's Senate to pass constitutional measures that would strip away Catalonia's regional powers in a bid to halt the region's bid for independence.
Mariano Rajoy's majority government would immediately sack Catalonia regional president Carles Puigdemont and his ministers should they be allowed to trigger Article 155 of the constitution allowing Madrid complete control over Barcelona.
Speaking ahead of the vote to approve direct rule, Mr Rajoy said the region would have to face the consequences for a "clear violation of laws".
Article 155 of the Spanish constitution allows the government to take "all measures necessary" to allow the government in Madrid to intervene directly in the running of an autonomous region in the event of a crisis. Known as the 'nuclear option', it has never been used before.
It would be the first time in four decades of democratic rule that the national government would directly run the affairs of one of Spain's 17 semi-autonomous regions.
Meanwhile, in Barcelona, separatist lawmakers filed a proposal for Catalonia's regional parliament to vote later on Friday on establishing an independent republic.
He said Spain faced a "challenge not seen in recent history" and measures by Madrid were aimed at restoring order and protecting the liberties of Catalans.
Mr Puigdemont scrapped hopes of a possible end to the political deadlock on Thursday when he opted not to call an early election himself and halt the drift toward independence.