By Diego Ore and Daniel Wallis
CARACAS (Reuters) - Acting President Nicolas Maduro vowed on Monday to stamp out corruption following days of accusations by his election rival Henrique Capriles that ruling party officials were plundering Venezuela's oil wealth.
Corruption has been a perennial problem in the country and was a primary campaign issue for the late socialist leader Hugo Chavez when he was first elected in 1998. His death from cancer last month triggered the April 14 election.
Polls show Maduro comfortably winning the election thanks to the goodwill generated by Chavez's social spending measures, although opposition critics had for years accused Chavez of allowing graft among allies to go unchecked.
"I'm going to pursue corruption where ever it is. I'll give my own life to combat corruption if it's necessary," Maduro, who Chavez endorsed as his successor, said at a campaign rally in the eastern city of Maturin.
"We've got great challenges to overcome bureaucracy, corruption and indolence of some officials who turn a blind eye to the problems of the people."
Opinion polls, which are controversial and divergent in Venezuela, give Maduro a double-digit lead over Capriles. The latest private survey by local pollster Datanalisis, cited by the Eurasia Group think tank, gave him 50.2 percent, compared with 32.4 percent for his opponent.
That was a wider gap than in a Datanalisis poll last month that gave Maduro 49.2 percent and Capriles 34.8 percent.
Capriles has in recent days promised to end special favors for those who are "plugged-in" - a reference to friends of party leaders who gain quick access to social benefits such as newly built homes while others remain stuck on waiting lists.
Chavez's first election in 1998 drew heavily on popular outrage over widespread corruption in the 1990s, when poverty rose dramatically as oil prices remained low.
But the issue became less important during his 14-year rule as rising oil prices spurred economic growth and Chavez used windfall revenue to build free health clinics and subsidized grocery stores and provide pensions to the elderly.
Corruption accusations during Chavez's presidency have focused almost entirely on opposition leaders or elected officials who defected from the Socialist Party ranks. Critics say he avoided pursuing charges against allies.
CEMENT TO COFFEE
Capriles, a 40-year-old state governor who lost a presidential election to Chavez last year, says Venezuela needs a fresh start after 14 years of Chavez's hardline socialism.
He says the frequent nationalizations under Chavez's government allowed corrupt officials to control the sale of products ranging from cement to coffee and require desperate buyers to pay bribes to access them.
Capriles wants to install a Brazilian-style administration of free market economics with strong social policies, although former Brazilian president Luiz Inacio Lula da Silva has publicly endorsed Maduro as his friend Chavez's heir.
Underlining the deep polarization that is one of the late leader's many legacies, police fired in the air as "Chavista" youths fought with opposition student protesters who had set up camp in a Caracas square to demand a fair election.
The government said seven of the students were injured in the clash, which took place in the capital's wealthy La Castellana district, in a plaza overlooked by three European embassies and a five-star hotel.
Interior Minister Nestor Reverol promised to investigate.
"We reject and condemn these developments," he told state television. "Wherever it comes from. We are going to investigate ... We call for peace and sanity."
Tensions have risen in recent days, fueled by dueling allegations of dirty tricks, and claims by hardliners on both sides that the others are planning violence.
Maduro has accused a Capriles campaign official of conspiring with mercenaries from El Salvador, who the acting president said had entered Venezuela with the aim of killing him and sabotaging the power grid to sow chaos.
The opposition, meanwhile, warned of a government plot to plant illegal arms and explosives on senior opposition officials in order to arrest them before Sunday's vote.
Maduro has also accused the U.S. government of plotting to kill Capriles and then blame it on his administration to trigger civil unrest. Washington denied it.
Capriles has ridiculed Maduro's claims and likened them to Chavez's many denunciations of assassination plots, which critics saw as attempts to distract voters from daily problems such as violent crime, high prices and creaking public services.
On Monday, a right-wing Salvadoran congressman dismissed accusations by Maduro that he was involved in a plot to kill him, saying that Venezuela's acting leader wanted to direct attention away "from what is really happening in that country."
(Additional reporting by Deisy Buitrago, Eyanir Chinea and Mario Naranjo; Writing by Brian Ellsworth and Daniel Wallis; Editing by Bill Trott and Doina Chiacu)