The Spanish government is preparing to activate a constitutional article to take control of the Catalonia region in a bid to stop a rebellion from separatist politicians.
Prime Minister Mariano Rajoy's Cabinet is meeting to outline the scope and timing of the measures the government plans to take under Article 155 of the Spanish Constitution.
Earlier, in an unusually emotional speech, Spain's King Felipe said the country should not give up on everything it had built, adding Catalonia "is and always will be" part of a larger Spain.
The previously untapped article allows central authorities to intervene when one of Spain's 17 autonomous regions fails to comply with the law.
Mr Rajoy could force the removal of Catalan officials and call early regional elections for as soon as January.
Opposition parties have agreed to support him in revoking Catalonia's autonomy. The specific measures need approval from the country's Senate.
Catalan leader Carles Puigdemont has threatened to call a vote in the regional parliament for an explicit declaration of independence from Spain.