BARCELONA, Spain (AP) — Voters in Catalonia participated in an election Sunday that could propel the northeastern region toward independence from the rest of Spain or quell secessionism for years.

Secessionists have long pushed for an independence referendum, but Spain's central government has not allowed one, arguing it would be unconstitutional because only it can call such a vote.

Sunday's election is for Catalonia's 135-member Parliament, located in the region's capital Barcelona. Secessionists argue that if they win 68 seats, the result would give them a democratic mandate to initiate a split from Spain that could include a unilateral declaration of independence.

The central government of Prime Minister Mariano Rajoy says it will use all legal means to prevent Catalonia from breaking away, an exit European leaders warn would include ejection from the European Union.

Polls have forecast a slim win for the pro-independence parties. But they also indicate that the leading bloc of separatist parties "Together for Yes" will likely need the support of the extreme left-wing CUP to cobble together a majority of seats needed to launch their push to sever century-old ties with the rest of Spain.

Catalans from both sides of the independence divide are fiercely proud of their Catalan language, which is spoken along with Spanish and was suppressed under three decades of Gen. Francisco Franco's dictatorship.

Jordi Perez was one of 5.3 million Catalans of the region's populace of 7.5 million called to vote on Sunday. The 50-year-old civil servant said he voted for "Together for Yes" because he feels Spain has historically disparaged Catalan culture and its language.

"I have wanted independence ever since I was young," Perez said after casting his ballot in Barcelona. "During three centuries they have robbed us of our culture. We have reached the moment that the Catalan people say enough is enough."

While the pro-independence camp has organized massive rallies of hundreds of thousands in recent years, those in favor of remaining a part of Spain have kept a low profile.

School teacher Sandra Guerrero, 30, said that these elections motivated her to vote for the first time. She voted for the Citizens party, which is against independence.

"We Catalans have the fame of all being separatists, but the truth is that I have voted No," Guerrero said. "My parents are from Andalucia (in southern Spain). People from outside Catalonia have always treated me well. I feel part of Spain. I am proud to be Catalan, but also to be Spanish.

"I had never voted before because I was disillusioned with politics. But this time I have because these are important elections."

Heckle reported from Madrid.