CARACAS, Venezuela (AP) -- Three Venezuelan opposition parties on Tuesday pulled out of congressional elections planned for Sunday, saying the conditions were tilted toward President Hugo Chavez's government.Henry Ramos, leader of the country's largest opposition party, Democratic Action, said the National Elections Council favored pro-government candidates and has failed to correct errors in the nation's voter registry."Imagine what it means to us for a party like Democratic Action to say today that under these conditions, we cannot participate in the electoral process," Ramos told a news conference. His party, founded in 1941, once dominated Venezuelan politics.Two other parties, Project Venezuela and the Social Christian Party, or Copei, later said they too were withdrawing."There are not conditions for voting," said Cesar Perez, Copei's secretary general.Chavez and his allies have vowed to expand their congressional majority to two-thirds, which would allow them to push through the legislature constitutional reforms that opposition leaders strongly oppose.During a speech to government supporters, Venezuelan Vice President Jose Vicente Rangel denied that Chavez held sway over the election council."The opposition says this election isn't clean. It's the cleanest in Venezuela's history, but they have interests opposed to the National Electoral Council," Rangel said."The Democratic Action party has withdrawn from the elections, very good! They can go to hell!" Rangel added.Lawmakers allied with Chavez control 52 percent of the 165-seat National Assembly.Democratic Action holds 23 of the 79 opposition-held seats -- more than any other opposition party -- and is the country's second oldest political party. The center-left party dominated politics from the fall of Venezuela's last dictatorship in 1958 until Chavez's meteoric rise to power in 1998.Ramos said his party is demanding a suspension of the elections until equal conditions exist for parties of all political leanings.Henrique Salas, president of Project Venezuela, which holds seven seats in the assembly, said the electoral council had shown bias in past elections."It's evident that we Venezuelans have the right to vote, but not the right to elect. We vote, but the National Elections Council elects," Salas told the Venezuelan TV channel Globovision. Salas is a former presidential candidate who was defeated by Chavez in 1998 elections.The announcements came a day after the election council decided high-tech thumbprint identification devices will not be used in the elections. Critics argued they endangered voters' confidentiality.Ramos said the council still had not convinced opposition candidates that the voting software did not endanger voters' confidentiality."The secrecy of the vote is not guaranteed," he said.Ramos denied Venezuelan government accusations that the opposition has been acting in the interests of the U.S. government, which is often critical of Chavez. He also took a dig at Chavez for forging close ties with Cuban leader Fidel Castro."We don't sit on the U.S. ambassador's lap, nor do we sit on the Cuban ambassador's lap," Ramos said. "We don't have assistance from the CIA or the Pentagon, or Fidel Castro's G2" security agency.Observers from the Organization of American States and the European Union are on hand for Sunday's vote.Members of the electoral council have repeatedly denied accusations of a pro-government bias.Observers have backed the results of past Venezuelan elections, including a referendum vote against Chavez last year that he won by a wide margin."We felt we were victims of fraud" in that vote, despite the observers' conclusion that the vote was clean, Ramos said.The National Assembly is being expanded by two seats to have 167 members after Sunday's election.Copyright 2005 The Associated Press. All rights reserved.This material may not be published, broadcast, rewritten, or redistributed.