Francisco Ameliach, a Venezuelan politician, said the National Assembly postponed a final debate on the "enabling law" until next Tuesday so that the text could be revised to make "totally clear" in which areas Chavez could pass laws unilaterally.
Many protesters said they fear what Chavez may do if the new measure gave him carte blanche to pass legislation on a broad range of areas without checks or balances.
"It gives him total power," said Greys Pulido, a 40-year-old protester. "We don't want a dictatorship."
|Chavez was re-elected president by a wide|
margin last month [EPA]
Another Chavez opponent, 70-year-old Maria Butto, said she came to speak out against what she feels is a slide towards communism.
"I don't want totalitarianism," she said.
Chavez, who was re-elected by a wide margin last month, says he is committed to democracy and overseeing changes that will give a greater voice in decision-making to poor Venezuelans.
Meanwhile, opposition leaders presented the National Assembly with a document demanding their voices be heard as the government draws up the "enabling law".
They also presented separate constitutional reforms that could eliminate presidential term limits that currently bar Chavez from running in 2012.
Former ally reacts
In a public rebuke, Luis Miquilena, a former Chavez confidant and cabinet member, said the president "is doing whatever he wants and doesn't abide by any rule".
The 87-year-old former interior minister said on Tuesday: "This is a government with a hypocritical authoritarianism that tries to sell the world certain democratic appearances."
Miquilena, a former communist and pioneer of Venezuela's labour movement, was a close collaborator who helped Chavez after he led a failed coup in 1992 against then-president Carlos Andres Perez.
He has largely maintained a low profile since resigning from Chavez's government in early 2002.
As Chavez's interior minister in 1999, Miquilena earned a reputation as being a conciliator between Chavez's fiery rhetoric and the nervous opposition, but left the government in 2002 after quarrelling with Chavez and denouncing his "autocratic style".