The Catalan regional parliament has voted to declare independence from Spain, just as the Spanish government appears set to impose direct rule.
The move was was backed 70-10 in a ballot boycotted by opposition MPs.
Spanish Prime Minister Mariano Rajoy earlier told senators direct rule was needed to return "law, democracy and stability" to Catalonia.
The crisis began when Catalans backed independence in a disputed vote earlier this month.
The Catalan government said that of the 43% who took part in the referendum, 90% were in favour of independence. But Spain's Constitutional Court had ruled the vote illegal.
Spain's Senate is still to vote on whether for the first time to enact Article 155 of the Spanish constitution, which empowers the government to take "all measures necessary to compel" a region in case of a crisis.
It would enable Madrid to fire Catalan leaders, and take control of the region's finances, police and public media.