BARCELONA, Spain -- The grassroots groups driving Catalonia's separatist movement defied Spanish authorities on Sunday by distributing one million ballots for an Oct. 1 independence vote that the central government in Madrid has called illegal and vowed to halt.

Jordi Cuixart, president of the separatist group Omnium Cultural, announced the ballots were being distributed during a rally in Barcelona.

"Here are the packs of ballots that we ask you to hand out across Catalonia," Cuixart said.

Spanish police have confiscated millions of ballots in recent days as part of a crackdown to stop the Oct. 1 vote, which has been suspended by Spain's constitutional Court. Around a dozen regional Catalan officials were arrested Wednesday, provoking a wave of protests across the prosperous northeastern region.

Catalonia's separatists have pledged to hold the vote regardless of the central government's wishes and rallied Sunday in public squares in Barcelona and other towns in the region. Many carried pro-independence flags and signs calling for the independence vote and urging the "Yes" side to victory.

The crowds were asked by secessionist politicians and grassroots groups to also print and distribute posters supporting the vote.

"I ask you to go out and vote! Vote for the future of Catalonia!" Carme Forcadell, the speaker of Catalonia's regional parliament, told a Barcelona crowd.

Polls show the 7.5 million residents of Catalonia are roughly split on breaking with the rest of Spain.