Opposition presidential contender Pablo Perez finished off his campaign Thursday urging public employees to join his supporters and vote in a primary election choosing a single challenger to face President Hugo Chavez.
The opposition coalition has accused the government of pressuring public employees not to vote in Sunday's primary, which is open to all of Venezuela's 18.2 million registered voters. The opposition has not provided evidence for its claim.
Perez, the governor of western Zulia state, marched through eastern Caracas accompanied by hundreds of supporters while a festive drum beat filled the air. He said at a rally that he has gained support among the poor.
The 42-year-old politician chided Chavez for talking so many hours on television, and pledged to instead be "a president who listens to the people."
Perez has been trailing in second place in recent opinion polls behind Henrique Capriles, a youthful state governor who has won a large following while promising to be a friend both to the poor and to business.
Capriles, who spoke to a rally of supporters in the central city of Valencia, said: "There's no obstacle that can stop a nation that wants change."
The winner among the five presidential contenders in Sunday's primary will be the opposition's unity candidate in the Oct. 7 election against Chavez, whose approval rating has been above 50 percent in recent polls.
Voters in the primary elections are also picking opposition candidates for other offices, including 17 state governor posts.
The Atlanta-based Carter Center said Thursday that it will send "a small study group of international experts" for the primary.
The center, founded by former U.S. President Jimmy Carter, said in a statement that the group's purpose will be to "learn the perspectives of key political actors, representatives of civil society, and election officials about the national electoral processes this year." It said the experts "will not constitute an electoral observation delegation."