The Spanish government will act if Catalan separatist leaders go ahead and declare independence on Tuesday as they have promised, Spain’s deputy prime minister has said.

Soraya Saenz de Santamaria told the COPE radio station on Monday that “if they declare independence, there will be decisions to restore the law and democracy”.

Catalan regional president Carles Puigdemont is to address the Catalan parliament on Tuesday evening to discuss the political situation following the disputed referendum won by the Yes side.

Protesters in SpainA man holds up a sign during a march in downtown Barcelona (Francisco Seco/AP)

The vote had been declared illegal in Madrid before it took place and fierce clashes erupted with police at polling stations.

Separatist politicians have said there will be a declaration of independence during that session, although some ruling coalition politicians say the move would be “symbolic”.

Ms Saenz de Santamaria also called for members of the Catalan government “who still respect democracy and freedom to refrain from jumping into the void”.