By Andrew Cawthorne
CARACAS (Reuters) - Authorities arrested three people on Monday suspected in the murder of an opposition leader that shook Venezuela and drew international condemnation in the run-up to this weekend's election for a new legislature.
Opposition leaders blamed last week's shooting of Luis Diaz, 44, a candidate for the Democratic Action party in central Guarico state, on the ruling Socialists.
But President Nicolas Maduro's government has furiously denied that. Officials say Diaz was a well-known criminal caught in a gang dispute linked to unions in Guarico, whose death was being manipulated to discredit the Socialist Party.
The Prosecutor General's Office named three men, aged between 22 and 28, whom it said were arrested on Monday morning in the town of Altagracia de Orituco where Diaz was killed at a rally.
"The three men will be accused in coming hours for their presumed link to Luis Manuel Diaz's death," the office said, without giving further details.
Diaz's murder has heightened Venezuelans' fears of volatility around Sunday's vote for a new National Assembly, which polls show the opposition could win for the first time in 16 years in the South American OPEC member.
Venezuela's economic crisis, including the world's highest inflation and widespread shortages from eggs to electronics, has battered the popularity of Maduro, who won election in 2013 after the death of his far more popular predecessor Hugo Chavez.
Though various polls show the opposition Democratic Unity coalition ahead on nationwide voting tendencies and anti-Maduro leaders are confident, electoral district geography and superior campaign resources favor the ruling party.
Also, the government retains a hard core of support from Venezuelans still devoted to the memory of Chavez and scared the opposition will dismantle state welfare projects.
"What is the plan of the rotten right-wing?" asked Maduro at a political rally in Caracas on Monday. "End the social missions, end the pensions and send old people to work ... Privatize education ... Bring the International Monetary Fund (IMF) here and give them our oil wealth."
Venezuela's opposition sent a message to the armed forces on Monday, urging them to respect Sunday's results and not block any potential change of power in the National Assembly.
One pollster, Luis-Vicente Leon, said even though Maduro's popularity had improved in recent days thanks to the government's strident campaign, the opposition was still hot favorite. "The question is how big a majority they achieve."
(Editing by Diego Ore and Grant McCool)