After Catalonia's president Artur Mas staked his leadership on the issue by calling the vote for November 9, the national government responded by filing a constitutional challenge.
Conservative Prime Minister Mariano Rajoy said he "deeply" regretted Mas's move.
"I regret it because it is against the law, it bypasses democracy and divides Catalans, it alienates them from Europe and the rest of Spain and seriously harms their welfare," Rajoy said.
He said the government had sent the appeal to the country's Constitutional Court and that Mas's measures would be suspended as soon as that tribunal accepted the appeal, pending a final decision by its judges.
"You cannot use the law to prevent people indefinitely from stating their opinion," Mas said in a television interview yesterday in anticipation of today's appeal.
"Voting on November is the best thing for everyone because it will allow us and also the Spanish government to know what the Catalan people's opinion is."
Rajoy insisted today that the right to decide on a region's status belonged to "all of the Spanish people" under the country's 1978 constitution -- the keystone of Spain's democracy after the death of the dictator Francisco Franco.
The appeal did not put off supporters of independence, who vowed to continue preparing for the vote regardless.
"We will not stand by idle after this suspension," said the spokesman for Mas's government, Francesc Homs, on Catalan television.
"We are committed to voting on November 9," said Oriol Junqueras, leader of the left-wing Catalan nationalist party ERC, which is allied with Mas's conservative CiU grouping in the regional parliament.
"We are aware of the great difficulties we will face in the coming days but we are ready to face those difficulties."
Scottish voters eventually chose not to be independent from Britain.
But like Scotland, Catalonia "wants to be heard and it wants to vote," Mas said after he signed a decree yesterday formally calling the vote.
Rajoy described the independence ambitions of the Scottish National Party and Catalonia as a "torpedo" to European integration.
Mas has vowed to let Catalans vote on breaking away but has also promised to respect Spanish law.
