The Spanish government has said it will suspend Catalonia's autonomy and impose direct rule if the region moves ahead with its secession bid.
After rejecting Catalan leader Carles Puigdemont's threat to declare independence unless talks are held, Spanish Prime Minister Mariano Rajoy said he would hold a cabinet meeting on Saturday (21 October) that could revoke the region's autonomy.
"If the central government persists in impeding dialogue and continuing its repression, Catalonia's parliament may proceed ... with a vote to formally declare independence," his letter to the Spanish government read.
The government quickly responded with a statement that it would hold a special cabinet meeting at the weekend in which it would trigger the process of activating Article 155 of Spain's constitution, which allows central authorities to take control of semi-autonomous powers of the country's 17 regions.
The meeting will "approve the measures that will be sent to the Senate to protect the general interest of all Spaniards," the statement said.
The constitutional law has never been used in the period since Spain became a democracy in 1978.
France has warned Catalonia that it will automatically be expelled from the European Union if the region declares independence.
"If there were to be a declaration of independence, it would be unilateral, and it would not be recognised," France's European affairs minister Nathalie Loiseau said on 9 October.
But another EU member state, Slovenia, said it would recognise an independent Catalonia. The deputy leader of Slovenia's social democratic party, Jan Skoberne, wrote on Twitter: "No need to be afraid. People of Slovenia stand with Catalonia. And I strongly believe that we will be among the first to recognize the new Republic."