Madrid, Mar 9: Voting got under way in Spain`s general election on Sunday, a ballot expected to return the ruling Socialists to power, though again short of an absolute majority after a tough campaign focused on a flagging economy.

Four years ago, then opposition leader Jose Luis Rodriguez Zapatero came from behind to win power on a wave of voter anger at the ruling Popular Party (PP), who tried to blame the ETA Basque separatists for election-eve bomb attacks by Islamic militants.

The killing of a former Socialist councilor in the Basque Country on Friday, which all major parties blamed on ETA, has again cast a pall over a Spanish election.

But political commentators say this time around, the attack is unlikely to radically change the outcome after a campaign dominated by worries over soaring immigration and the end of an economic boom.

Polling booths opened at 8:00 GMT (4 a.m. EST) and turnout is key to the result, particularly among young voters, who helped to boost participation to 76 percent in 2004 in outrage at what they saw as PP efforts to cover up who was really responsible for the bombings.

Commentators said Friday`s murder of the former councilor Isaias Carrasco might again boost the turnout.

That could help the Socialists, as PP supporters tend to be more reliable voters.

Dry and stable weather in most of Spain may also encourage Spaniards to take part in the ballot.

Opinion polls published on Monday -- the last day before a pre-election moratorium -- showed the Socialists on 43.4 to 43.9 percent and Mariano Rajoy`s PP at between 39.3 and 39.5 percent.

Economy in focus

Economists say growth could fall as low as 2.0 percent this year -- a rate not seen since the early 1990s -- from more than 4 percent a year ago as a global credit squeeze chokes Spain`s already-cooling property sector.

The sector accounts for almost a fifth of Spain`s GDP and jobs. Unemployment, which hit a 29-year low last year, is up by almost 300,000 since June to 2.3 million.

Highly indebted Spaniards, already struggling to meet higher mortgage repayments, are suffering from racing food and fuel prices that pushed inflation to a record 4.4 percent in February.

Many are also unsettled by an unprecedented influx of more than 3 million registered immigrants in the last eight years -- most of them from Morocco, Eastern Europe and Latin America.

Socialist supporters say a win for their party would finally silence PP gripes that the bomb attacks in 2004 robbed them of rightful victory.

The 2004 election upset ushered in four years of particularly bitter political confrontation focused on the train bombings, ETA, regional autonomy and Zapatero`s program of liberal policies such as legalizing gay marriage.

Analysts say a turnout of less than 75 percent would harm the Socialists, and that a turnout below 70 percent could even tip the scales towards a conservative victory.

The PP has openly acknowledged that it is trying to get left-wing voters to abstain.

In any case, neither big party is likely to be able to govern without some form of support from regional or leftist parties, with whom the Socialists have made ad hoc alliances over the last four years.