Catalonia's regional president, Carles Puigdemont, told a meeting of his party he would formally declare independence if Spain starts the process of suspending the region's autonomy on Thursday, a Catalan government source said on Wednesday, according to Reuters.
Madrid has given Thursday as a deadline for the regional government to back down from a symbolic independence declaration made last week.
If Spanish Prime Minister Mariano Rajoy moves to apply direct rule on Thursday, it will take between three and five days for regional autonomy to be effectively suspended.
Catalan lawmakers last week signed a document declaring independence from Spain, but delayed its implementation in order to allow for negotiations on the issue with the Spanish government.
Puigdemont says Catalans have earned the right to independence from Spain after a referendum held on October 1.
The central government in Spain does not accept the declaration of independence by the separatists and does not consider the referendum or its results to be valid.
The Spanish government attempted to prevent the vote from taking place. Nearly 500 people were wounded in clashes with police on the day of the vote.