( dpa )- Spaniards began voting Sunday in parliamentary elections expected to become a close race between the governing Socialists and the opposition conservatives after a killing by the militant Basque separatist group ETA cast its shadow over the vote.
About 35 million people were eligible to elect 350 members of parliament.
Polls had given Prime Minister Jose Luis Rodriguez Zapatero's Socialists a lead of about 4 per cent over the opposition conservative People's Party (PP) headed by Mariano Rajoy .
But the shooting of former Socialist councillor Isaias Carrasco in the Basque town of Arrasate on Friday increased uncertainty over the election result.
ETA's fifth killing during Zapatero's legislature made it seem possible that more voters might choose the PP because of its tougher line on ETA.
Yet the killing was also expected to help the Socialists by mobilizing their traditionally more passive voters.
Zapatero had pledged to seek an absolute majority to be able to govern without the support of smaller leftist and regionalist parties, as he has done until now.
Zapatero took a surprise victory after eight years of conservative rule in 2004 after Islamist extremists killed 191 people in the Madrid train bombings three days before the poll.
Many voters attributed the attack to the then conservative government's alliance with the United States in Iraq and suspected the government of lying when initially blaming the bombings on ETA.
The subsequent legislature was characterized by constant tension between the opposition and the government, with the PP strongly condemning Zapatero's failed attempt to negotiate with ETA.
The electoral campaign has also been unusually virulent, with Zapatero and Rajoy accusing each other of lying during two live television debates watched by more than 10 million people.
The Socialists' biggest weakness was thought to be the economy, which has slowed down after a decade-long boom.
Unemployment, which had dropped from 22 per cent in 1996 to around 8 per cent, has started going up again, partly because of a meltdown in the construction sector, and indebted consumers are struggling with rising food and fuel prices.
The PP has also accused the government of not controlling the entry of illegal immigrants, whose number the party has put at more than a million, while Zapatero and newspaper reports estimated it at up to 250,000.
In addition to disputes about anti-terrorism policy, Zapatero's term in office has been marked by sweeping social reforms which have contributed to transforming Spain from a conservative Catholic country to one of Europe's most liberal ones.
Reforms included major women's rights legislation, including electoral parity. The parties have at least 40 per cent of female candidates in Sunday's elections.
The Zapatero government also gave homosexuals full marriage rights, including the right to adopt children. It adopted a comprehensive law against domestic violence, made divorce easier, and reduced the Catholic Church's influence on education.
The reforms put Zapatero on a collision course with the church, but the PP has refrained from attacking them head-on.