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Billionaire businessman Sebastian Pinera is heavily favored to top Sunday's election backed by Chileans who hope the former president can resuscitate a flagging economy, but polls suggest he won't get enough votes to avoid a runoff.

The world's top copper producing country has been hurt by lower international prices and demand for the metal that is the backbone of its economy.

The Harvard-educated entrepreneur is proposing to cut taxes on businesses to promote growth and promises to launch a $14 billion, four-year spending plan that includes fresh investments in infrastructure.

Pinera, 67, struggled with large protests over inequality and education during his 2010-2014 presidency and he ended his term with low popularity ratings. But the economic slump and overall disenchantment with the center-left government of President Michelle Bachelet has given him a boost in this election.

Bachelet was Chile's most popular president during her first 2006-2010 term, but she is ending her 2014-2018 presidency as the least popular. In addition to economic woes, her image was hurt by a real estate scandal involving her family, though no charges were brought.

Pinera is also expected to be aided by lower turnout as voting was made voluntary rather than mandatory in 2012. He may also be favored by a fractured center-left coalition that has been questioned by Chileans who feel Bachelet wavered in her promises of profound social changes in labor and education.

Polls give Pinera a wide margin over his nearest competitor, center-left Sen. Alejandro Guillier, but not enough for him to win the election outright. If no candidate gets more than 50 percent of the vote it heads to a runoff between the two top vote-getters. Six other candidates are also running in the election.

Guillier, a 64-year-old former journalist, promises to continue Bachelet's plan to increase corporate taxes to partly pay for an education overhaul, reform the constitution and improve the pension and health care system. He also wants to diversify Chile's resources and develop alternative sources of energy to lower investment costs.

The elections also choose 155 members of the lower House of Congress and 23 seats are up for grabs Senate