The Spanish government will act if Catalan separatist leaders declare independence on Tuesday, the deputy prime minister has said.
Soraya Saenz de Santamaria told COPE radio that “if they declare independence, there will be decisions to restore the law and democracy”.
Catalan regional president Carles Puigdemont will address the Catalan parliament on Tuesday evening following the disputed referendum won by the “Yes” side.
The vote had been declared illegal in Madrid before it even took place, and violent clashes erupted with police at polling stations.
Initially it was thought separatist leaders could move to declare independence as early as Monday night, but the address has been pushed back a day.
Catalonia’s High Court has asked the national police to provide extra security at the court building in case the declaration is made.
In a statement, it said the decision was made to increase the security of the building and to “guarantee its full and normal operation”.
Separatist politicians have said the declaration of independence will take place on Tuesday, although some say the move will be “symbolic”.
Ms Saenz de Santamaria called for members of the Catalan government “who still respect democracy and freedom to refrain from jumping into the void”.
On Sunday, hundreds of thousands of pro-unionists protested in Barcelona against the referendum.
Both sides have shown no sign of entering into talks in what is the largest political crisis in Spain since it became a democracy four decades ago.
France, which borders Catalonia, said on Monday it would not recognise a unilateral declaration of independence.
Spain Prime Minister Mariano Rajoy has not ruled out removing the Catalan government and calling fresh regional elections.
He has also threatened to suspend the region’s existing autonomous status.
Catalan authorities say more than 90% who voted backed independence, although opinion polls suggest it is much closer.
Turn out for the referendum was just 43%.
Around 900 people were injured when officers used rubber bullets and batons against voters at polling stations.