Catalan President Artur Mas has vowed to step up the pressure for independence after a symbolic vote in the region on Sunday.
More than two million people cast their vote; early results show 80% voted in favour of breaking away from Spain.
Mas says he will send a letter to the Spanish prime minister, Mariano Rajoy, urging him to confront “the Catalan question” with a formal, binding referendum on independence.
In the Spanish capital Madrid, there was disappointment and anger amongst some locals on Monday at the vote.
One Madrid local said: “It is totally undemocratic. They have not asked all Spaniards. Catalonia is ours, it belongs to Spain.”
Another said independence would never work: “Nationalism is a romantic idea, but I reckon nowadays it is not possible. From the economic point of view it cannot be supported. What happened yesterday is just another demonstration.”
The symbolic vote was planned after an official referendum on independence was suspended by Spain’s Constitutional Court with the government challenging it as unconstitutional. The court then suspended the symbolic vote on the same grounds. The Catalan government ignored the suspension, manning polling stations with 40,000 volunteers.
In Barcelona, there was defiance and pride that the vote had taken place. One woman said: “Today I feel proud of being a Catalan and being able to express my opinion. And what I ask them is please, let us decide on what we want to do.”
Another said: “We need to start a dialogue. Catalans feel the need to be heard. That feeling has not been considered by the Spanish government.”
Spanish state prosecutors are now investigating whether the Catalan government has broken the law by holding the informal vote.