The Spanish government said Thursday it would begin the process to impose direct rule on Catalonia in an unprecedented move to crush the region's independence bid.
In a statement from Madrid, the government of Prime Minister Mariano Rajoy said it would invoke Article 155 of the constitution, a provision that allows the central government to suspend the autonomy of the Catalan regional administration.
The statement did not spell out exactly what steps it would take.
Spain's Senate, controlled by Spanish Prime Minister Mariano Rajoy's Popular Party, would have to vote to approve Article 155 before it could be brought into effect in Catalonia.
The announcement came minutes after Catalan President Carles Puigdemont threatened that the region could formally declare independence if the Spanish government does not engage in dialogue.
Puigdemont also demanded Spain end its "repression" of Catalan independence leaders, in a letter sent shortly before a Madrid-imposed deadline for the region to drop its independence bid.
"The decision of triggering Article 155 falls to the Spanish Government, with the authorization of the Senate," he wrote. "Despite all our efforts and our will for dialogue, the fact that your only answer is canceling our autonomy indicates that that you do not understand the problem and do not wish to talk.
"Finally, if the Spanish Government insists in avoiding dialogue and continuing with oppressive measures, the Catalan Parliament will have the right, if thought necessary, to vote a formal declaration of independence, which was not voted on 10 October."
Under Spain's 1978 constitution, Catalonia and other regions such as the Basque country enjoy wide autonomy.
