The president of Spain's powerful north-eastern region of Catalonia has formally called an independence referendum, the latest secession push in Europe and one of the most serious challenges to the Spanish state of recent years.
The Spanish government of Prime Minister Mariano Rajoy insists the referendum, planned for November 9, is illegal and will not take place.
Catalan leader Artur Mas signed the decree to call the referendum in a solemn ceremony in the regional government headquarters in Barcelona today, flanked by most of the region's political leaders, who support the vote.
"Like all the nations of the world, Catalonia has the right to decide its political future," said Mr Mas. "We want to vote and we want to decide and now we have to means to do so."
He made the long-expected announcement as Mr Rajoy was flying back from China.
The premier is expected to hold an emergency cabinet meeting on the issue within days. The Spanish government plans to challenge a recently-passed Catalan law permitting the independence referendum before the Constitutional Court, which it hopes will suspend it and halt the vote.
Spain's constitution does not allow referendums on sovereignty which do not include all Spaniards, and experts say its Constitutional Court would rule the vote illegal.
Mr Mas has said he will not do anything illegal but insists the vote will be held. He has suggested that if a referendum cannot be held he may call early elections, which could be turned into a Yes or No vote on independence.
"We are open to negotiating the conditions of the referendum until the last moment," he said.
Pro-independence sentiment in the economically strong region has surged in recent years, fuelled by a sense that it deserves better fiscal and political treatment from Madrid.
While Mr Mas called the referendum, hundreds of pro-independence supporters gathered in the square in front of the Catalan government building in the centre of Barcelona, with many wearing or waving pro-independence flags and chanting "Independence".
The announcement comes a week after Scotland voted against breaking away from Britain.
Unlike the Scotland vote, a pro-secession result in a referendum in Catalonia would not result directly in secession butMr Mas says it would give him a political mandate to negotiate independence.
In the referendum, he wants to ask Catalans two questions: first, if they think Catalonia should be a state, and, if so, should it be independent.
Polls indicate most Catalans favor holding the referendum but are roughly evenly split on independence. Pro-independence fervour fades when people are asked if they favour an independent Catalonia outside the European Union, as the region has been warned would happen.
The referendum has stirred debate about whether the 1978 Spanish Constitution should be updated to accommodate Catalonia's demands for more power while maintaining the 17-region country unified. Separatist sentiment is also very strong in the northern Basque region.