The government said ministers would meet to activate Article 155 of
the constitution, allowing it to take over running of the region.
Catalonia's leader said the region's parliament would vote on independence if Spain continued "repression".
Catalans voted to secede in a referendum outlawed by Spain.
Some fear the latest moves could spark further unrest after mass demonstrations before and since the ballot on 1 October.
Spain's
supreme court declared the vote illegal and said it violated the
constitution, which describes the country as indivisible.
Article
155 of the constitution, which cemented democratic rule three years
after the death of dictator General Francisco Franco in 1975, allows
Madrid to impose direct rule in a crisis but it has never been invoked.
BBC
Madrid correspondent Tom Burridge says that for Madrid this is about
upholding the rule of law in Catalonia, protecting the Spanish
constitution and disciplining what it sees as an unruly, disobedient
devolved government.
