By Nelson Renteria
SAN SALVADOR, Jan 29 (Reuters) - A former guerrilla commander hopes to keep his left-wing party in power in El Salvador's presidential election on Sunday, but he faces a strong challenge from a right-wing rival who wants to use the army to battle powerful street gangs.
Polls give Vice President Salvador Sanchez Ceren of the leftist Farabundo Marti National Liberation Front, or FMLN, an edge over his conservative adversary Norman Quijano, who stepped down from a second term as mayor of San Salvador to run.
But with three main candidates competing, Sanchez Ceren is expected to fall short of the 50 percent support needed to win outright and so face Quijano in a run-off on March 9.
Antonio Saca, who was president from 2004 until 2009, lies a distant third in polls but his supporters votes will likely decide the winner if the election goes to a second round.
Saca broke away from the main right-wing party, the Nationalist Republican Alliance (Arena), which is backing Quijano. It is unclear if Saca's supporters would vote for Sanchez Ceren or Quijano in a runoff.
The tight race reflects a deeply divided society, where a middle class living in gated communities fears the power of gang members running poor slums. Whoever wins will have to contend with a divided Congress and sluggish economic growth.
Some 75,000 people died in El Salvador's 1980-1992 civil war, when the FMLN fought a string of right-wing governments that received military backing from the United States.
Sanchez Ceren has warned Quijano's proposals to tackle violent gangs would lead to a return to the country's dark days.
"We are going to bring peace to the people of El Salvador, but not by being a government that violates the constitution. We are not going to militarize the country," Sanchez said in his last campaign speech.
At the end of the war, the FMLN became a political party and it won power five years ago. It had fielded former guerrilla leaders as candidates before but it finally won the presidency when it backed Mauricio Funes, a journalist without any blood on his hands. Sanchez Ceren was appointed as his vice president.
The 69-year-old Sanchez Ceren worked as a rural teacher before joining the leftist guerrillas, eventually becoming one of the leaders of the FMLN's five main groups in the war.
Arena's election campaign has used images from when Sanchez was a guerrilla chief to stir up fears among voters.
A post-war Truth Commission laid most blame for wartime atrocities with the armed forces and right-wing death squads, but also found that the FMLN carried out executions and kidnappings, including Sanchez Ceren's faction, the Popular Forces of Liberation.
Still, the FMLN has made a risky bet by backing Sanchez Ceren.
"I don't trust him because he was a guerrilla commander," said 62-year-old seamstress Emelina Hercules. "They want hold onto power like dictators."
MORE WELFARE, LESS CRIME
Sanchez Ceren has vowed to reduce high levels of poverty, create jobs and lower the high crime rates attributed to the street gangs.
He also promises to expand welfare programs initiated by Funes' government, such as free school supplies or students and pensions for the elderly, that are popular in a country with a stagnant economy that depends on cash sent home by Salvadorans living in the United States.
El Salvador's debt has been rising and Wall Street agencies have warned they could cut its debt ratings this year amid weak growth and political gridlock.
Quijano wants to invoke presidential powers to use the army to fight gangs. He also wants to draft 18- to 30-year-olds who do not study or work into the army and subject them to military courts if they commit gang crimes.
Quijano has alleged a secret pact between the government and the two main gangs is behind a now two-year old truce, which was brokered by leaders in the country's brutal prisons.
The deal between the Mara Salvatrucha (MS-13) and its rival, Barrio 18, is credited with cutting one of the world's highest homicide rates down by half, with murders hitting a 10-year low in 2013.
The U.S. government underscored the gangs' growing power when it added the MS-13 last year to its black list of global crime organizations.
Quijano, 67, is a former dentist who joined Arena and became San Salvador's mayor. He says he will be able to cut crime and entice more investment to lift economic growth.
"We have a country that has been overrun by criminals," Quijano told Reuters. "The constitution gives you the power, when you are overwhelmed ... When you have lost peace, you can use the armed forces."
Quijano said he was inspired by Honduras' new president Juan Hernandez, who won on a pledge to use the military to fight drug gangs. Others are worried by Quijano's plan in a country where many still remember the military-controlled death squads before and during the civil war.
Funes, the outgoing president, has had a major role in the campaign, using his position to publicize corruption allegations against Francisco Flores, a former president from the Arena party and an advisor to Quijano's campaign. (Writing by Michael O'Boyle; Editing by Dave Graham, Kieran Murray and Marguerita Choy)