In a move unprecedented since Spain returned to democracy in the late 1970s, Prime Minister Mariano Rajoy said he would hold a special cabinet meeting on Saturday that could trigger the move, Reuters reported.
The Socialist opposition said they backed the government but suggested the measures should be limited in scope and time.
Catalan president Carles Puigdemont, ignoring a 10 a.m. deadline to drop his secession campaign, threatened Rajoy with a formal declaration of independence in the Catalan parliament.
Spain had threatened to take direct control of the autonomous region if Puigdemont fails to meet the 08:00 GMT (4 a.m. EDT) Thursday cutoff.