Venezuelan opposition leader Henrique Capriles announced on Sunday night that he will run in elections to replace Hugo Chavez, launching what many consider a doomed candidacy with a no-holds-barred attack against a government he said had coldly betrayed Venezuelans' trust.

Not only did Capriles slam the government for what he sees as using Chavez's death to push the candidacy of Nicolas Maduro, but implied that Maduro may have lied about when the late leader actually died.

He accused Maduro, who was sworn in as acting leader Friday, of playing "with the hope of millions of Venezuelan people."

"You had everything planned," Capriles said.

The government says Chavez succumbed to cancer on Tuesday after a nearly two-year battle. It has offered almost no clinical information.

With a picture of Chavez behind him, Maduro appeared on TV after the speech to respond to what he said was “the losing, miserable candidate” who had dishonored the late president.

He called Capriles a “fascist” who was trying to provoke violence and a coup against the state.

"We reject an infamy that you plan to hurl and the words you've said about the crystalline, pure image of Commander Chavez," Maduro said.

Mixed reactions

'I carry this country in my heart'—Henrique Capriles, Venezuelan opposition leader

Capriles, who is governor of Venezuela's biggest state, acknowledged that he faces tough odds against an official candidate in control of vast public resources who he said has the backing of the country's electoral commission.

But Capriles maintained his aggressive campaigning against candidate Maduro, telling Venezuelans that motivation for his actions stem from a love for his country.

“I'm going to fight for this country whatever the price I have to pay for it,” said Capriles. Because I carry this country in my heart, because you are not the "good" and we "the bad" — we are the millions who love this country."

His supporters responded by taking to the streets to celebrate.

Car horns sounded and people cheered for the opposition candidate. "I think he's the man that our country needs to unify it, Venezuela really needs it," said taxi driver Luis Villahermosa.

"We're happy, so happy, and we're going to win!" shouted one woman as she drove away from Capriles' eastern Caracas campaign headquarters.

But Ramon Romero said the opposition's tough tone will not help them at the polls, and had no chance of victory in any case.

"Now their odds are even worse," said the 64-year-old waiter and staunch Chavez supporter. "They don't care about anyone, and we (the voters) have been lifted out of darkness."

Venezuela's election commission has set the vote for April 14, with formal campaigning to start just 12 days earlier.