MADRID (AFP) ― A wave of nationwide protests against soaring unemployment and the economic crisis overshadowed local elections in Spain on Sunday in which the ruling Socialist Party faced the prospect of a humiliating defeat.

The predicted rout would be a bad omen for the party ahead of general elections scheduled for March 2012, when the conservative Popular Party is expected to romp back into office after eight years in opposition.

More than 34 million people are eligible to vote Sunday, choosing 8,116 mayors, 68,400 town councilors and 824 members of regional parliaments for 13 of the 17 semi-autonomous regions.

Polls forecast devastating losses for the Socialists as voters take revenge for the destruction of millions of jobs and painful spending cuts, including to state salaries.

They predict the ruling party of Prime Minister Jose Luis Rodriguez Zapatero will lose control of strongholds such as the cities of Barcelona, Seville and in the central region of Castilla-La Mancha.

It could even be short of an absolute majority in all the 13 regions.

Candidates from the two main parties have exchanged barbs over the economy and political corruption.

But the campaigning and the predicted outcome have been largely obscured ― and muddied by ― a nationwide protest movement that began May 15 by youths angry over joblessness, the economic crisis, politicians in general, and corruption.

“The angry and the undecided decide today,” headlined the left-leaning newspaper Publico on Sunday. “The effect of the protests becomes the main unknown of the regional and municipal elections.”

“From the streets to the polls,” said Barcelona-based Periodico de Catalunya.

Thousands of people have massed in city centers across the country in the biggest spontaneous protests since the property bubble burst in 2008 and plunged Spain into a recession from which it only emerged this year.

The crisis pushed Spain’s unemployment rate to 21.19 percent in the first quarter of this year, the highest in the industrialized world.

For under-25s, the rate in February was 44.6 percent, and some 800,000 young people are eligible to vote for the first time on Sunday.

Zapatero has voiced sympathy with the protesters, saying they are merely reacting “in a peaceful manner” to unemployment and the economic crisis.

The government has also resisted ordering police to disperse the demonstrators, apparently fearing it could hurt the Socialists at the polls.

Thousands of demonstrators, mostly young people, late Saturday filled Madrid’s Puerta del Sol square, where a ramshackle protest “village” has sprung up, in a gathering that lasted into the early hours of Sunday.

Demonstrations were also held in some other cities, including Valencia and Barcelona.

Much of the focus on Sunday was also on the northern semi-autonomous Basque Country, where a new political force, Bildu, is taking on the traditional parties after a court battle to prove it is not a mouthpiece for armed separatist group ETA.

Polls predict Bildu will leap into third place in the Basque Country behind the Basque Nationalist Party and the Socialists, beating the main conservative opposition, the Popular Party, in Sunday’s vote.

Polls open at 9 a.m. and close at 8 p.m. with first results expected between 10 p.m. and 11 p.m.