Opposition leader Henrique Capriles will campaign across Venezuela seeking to dispel the "lies" of Hugo Chavez's preferred successor as they duel for the presidency, a coalition leader said.
Leopoldo Lopez, a key member of Mr Capriles' campaign team, said their strategy is to press the message that Mr Chavez's protege and former vice president, Nicolas Maduro, also shoulders responsibility for the government's failures.
Mr Chavez died last week after 14 years in power and a two-year battle with cancer. The centrist Mr Capriles, 40, is the governor of Miranda state. He is trailing in polls behind former trade unionist Mr Maduro, who is now acting president.
"The government is going to carry the shield of Chavez's funeral and we are going to carry the shield of truth and respect," Mr Lopez, 41, told Reuters. "From today on, we are going to campaign to unmask the government's lies."
The opposition accuses Mr Maduro of misleading Venezuelans about the gravity of Mr Chavez's illness, pretending to have held a five-hour working meeting with him just three days before his death, and lying about major national issues such as a recent currency devaluation and the causes of inflation.
The opposition is hoping turnout will slip among 'Chavistas' and it can attract support from swing voters who made up 10-15 per cent of the electorate in the last presidential election in December.
"Henrique is going to crisscross the country. It won't be a campaign done from Caracas or done from TV cameras. It's going to be difficult, not just because the campaigning is going on during the funeral, but because it is being marked by the abuse of power, lies and scandals," Mr Lopez said.
"Some people could abstain because voting for Chavez is not the same as voting for the other candidate. And it is up to us to maximize turnout."
Mr Capriles ran an exhausting "house-by-house" campaign for most of 2012 up to the October election, traveling to the remotest parts of Venezuela in an effort to emphasize his personal stamina and draw attention to grassroots problems.
There is far less time in this campaign, but Mr Capriles still plans to reach all Venezuela's 23 states in the coming month, mixing walkabouts with rallies, aides said.
"This is going to be a tough campaign, maybe tougher than the last ones," said Mr Lopez.
Mr Lopez, who runs the Popular Will movement that is part of the opposition coalition, said the political landscape has changed dramatically since the election in October that gave self-styled socialist Mr Chavez a new mandate.
"The government will do everything possible to wrap the race in Chavez. Maduro does not have his own vision. His only electoral offering is to be Chavez's spokesman," he said.
Mr Chavez left behind a polarised country.
The poor adored his populist touch. He was jovial with friends, antagonistic with "imperialist" enemies, and captivated audiences by telling jokes or singing folk songs.
His opponents, many of them from Venezuela's middle class and elite, say he squandered vast oil wealth, politicized the judiciary, centralized power, and wrecked the economy.
Mr Capriles has accused Mr Maduro of using Chavez's coffin as a campaign prop and said the Supreme Court ruling that allowed Mr Maduro to stay on as acting president without stepping down to run was a farce.
In a war of words, Mr Maduro has called Mr Capriles a miserable fascist and a buddy of US "imperialists."
"We have a race of just 30 days, full of abuses, designed by the government to make us give up," said Mr Lopez.
"In the context of what's happening, we can't respond with flowers when they are throwing sparks, or with kisses when we receive threats."
Mr Lopez's movement accused the government of running a dirty campaign against it by distributing leaflets yesterday that used the party's logo and Mr Lopez's image, fist raised, alongside a call for Venezuelans to "set fire to the streets".
Government officials were not immediately available to respond to the opposition's allegation.