Thousands of people marched to the offices of the federal tax agency Tuesday and ripped up their tax forms, part of a month-old strike intended to force President Hugo Chavez from office.

Venezuela's opposition has called on citizens to stop paying taxes. Chavez, in a speech that he ordered broadcast on all television and radio stations, said the government will "take all actions necessary to make sure every last cent is paid because it belongs to the people."

The government warned that tax evasion can carry up to seven years in prison.

"It's not only a criminal action. It's also anti-national and threatens efforts to create a stable tax system," said Elias Eljuri, an officer of the Seniat tax agency.

Several thousand citizens ripped up tax forms outside the tax agency following the march in Caracas, one of several slated across the country.

The march was also meant to pressure Chavez into accepting a referendum over whether he should quit. Opponents said they will hold the vote even if Chavez ignores it, as he says he will.

"The referendum will happen with or without the participation of this regime," said Carlos Ortega, president of the 1 million-member Venezuelan Workers Confederation and leader of the general strike against Chavez.

Venezuela's state-owned oil monopoly is trying to break the strike by dividing the company into two parts to eliminate a faction of dissident managers based in Caracas.

Energy Minister Rafael Ramirez said last week the government won't hesitate to cut more jobs at Petroleos de Venezuela S.A. because of an "excess in bureaucracy." He said about 6,000 people are employed in Caracas and the western oil town of Maracaibo.

PDVSA wants to split its operations into eastern and western divisions to eliminate the opposition-dominated bureaucracy based in Caracas, Ramirez said.

Ortega's workers confederation, Venezuela's biggest business chamber and a range of civic and political groups withstood attacks by Chavez street thugs in November to deliver 2 million signatures demanding a nonbinding referendum on Feb. 2.

They buttressed their demand with a Dec. 2 strike that has hamstrung Venezuela's oil industry, a top supplier to the United States and the world's fifth-largest exporter. The strike -- and the prospect of war in Iraq -- has helped push oil prices beyond $30 a barrel.

Chavez, a former army officer who staged a failed coup in 1992, was elected president in 1998 and re-elected in 2000.

Cesar Gaviria, secretary-general of the Organization of American States, said his mediation efforts -- two months old now -- to solve Venezuela's crisis depend on a pending Supreme Court decision on the legality of the nonbinding vote.

Chavez refused a request by the National Elections Council to fund the vote. Ortega and other strike leaders are collecting money to pay for it -- the cost estimated at $22 million -- while the council says it may ask the OAS and other international bodies to help pay for the ballot.

"What are you afraid of? Why don't you want to be counted?" Ortega asked Chavez during a nationally televised news conference Monday.

Chavez has never answered such questions. He cites his hand-crafted Venezuelan constitution, which allows only for a binding referendum halfway into a six-year presidential term. In Chavez's case, that would be August.

Chavez's standing in popularity polls has remained at a consistent 30 percent since he was briefly overthrown in an April coup -- a high percentage among Latin American leaders. But some recent polls suggest as many as 90 percent of Venezuelan voters -- many of them so-called "chavistas" -- want elections now, well before Chavez's term ends in January 2007.

His term has seen incessant political unrest, a rapidly shrinking economy, ballooning unemployment, an increasingly feeble currency, endemic poverty and inflation surpassing 30 percent.