Thousands of Catalan separatists gathered in Barcelona on Sunday to protest a series of legal challenges made by Spain's government against pro-independence Catalan politicians.
Several of Catalonia's lawmakers are facing court cases sought by the Spanish government for having staged a secession referendum in 2014 in disobedience of a court order and for other regional laws designed to prepare a path toward secession.
Those politicians include Catalonia's former regional president, Artur Mas, and the current speaker of the regional parliament, Carme Forcadell, who both attended Sunday's protest.
Grassroots groups said they organized a fleet of around 150 buses to bring protesters in from the countryside and smaller towns to participate in the rally held near the Plaza de Espana in Barcelona.
Jordi Cuixart, the president of Omnium, a separatist grassroots group, told the crowd that teemed with pro-independence flags that he had "a message for the Spanish state."
"If you attack our democratically elected representatives, you attack our institutions, all our people and our sovereignty, and we will never allow that," Cuixart said. "Our cause is democracy and we will never let our elected representatives down."
Separatist sentiment has been on the rise in recent years in the wealthy northeastern region that speaks Catalan along with Spanish. Separatists complain that Catalonia pays more taxes than it should to the central government.
In 2014, then-president Mas ignored an order by Spain's Constitutional Court to suspend a mock referendum on Catalan secession. Mas' regional government went ahead with the informal poll anyway, staffing voting stations with volunteers. Nearly 90 percent of the ballots were in favor of independence, but only 2 million of the 5.4 million eligible voters cast ballots.
Polls consistently show that Catalonia's 7.5 million residents are about equally divided on breaking century-old ties with the rest of Spain.
Catalonia's current regional president, Carles Puigdemont, plans to call another referendum on independence by September.
"These are situations that can only be solved politically," Puigdemont said at a separate rally in his home village on Sunday.
Spain's government has consistently said that regions don't have the constitutional right to hold a referendum concerning the integrity of the country.