Thousands marched in Madrid Saturday to protest the government's recognition of ETA and to prohibit those associated with the group from seeking political office.
Earlier this week, thousands marched in the city of Bilbao, the largest city in Basque Country, in support of the Sortu party after the Supreme Court ruled the party had too close a ties to ETA.
ETA is viewed as a terrorist organization by many, including Spain, the United States and the European Union. It strives for the formation of an independent Basque state.
"We demand the government stops ETA sympathizers from accessing taxpayers' money by getting themselves elected to public office," said Conchita Martin said to the Associated Press. Her husband, Col. Pedro Antonio Blanco, was killed by ETA in 1999.
Banners are the rally in Madrid read, "For the defeat of terrorism: ETA barred from elections." Opponents of ETA do not want public money going towards funding ETA.
ETA declared a cease-fire last September and said it would be a permanent one in January.
The separatist group has called 11 truces throughout its 40-year history of fighting for independence, according to the Canadian Press.
In March, after strong urging from the government, the Spanish Supreme Court rejected Sortu's application to be legalized so it could take part in upcoming local elections in May. The government argued Sortu was an "extension" of Batasuna, the political branch of ETA.
Press TV reports separatists believe approximately 15 percent of the Basque population would vote for Batasuna.