Perpetual power
But Luis Miquilena, a former mentor to Chavez, urged Venezuelans to reject the proposed constitutional changes, saying the president would use them to govern indefinitely.
Miquilena, who headed a popularly elected, pro-Chavez assembly that drafted Venezuela's existing constitution, called his former ally's new reform proposal "a constitutional fraud" aimed at giving him "perpetual power".
"The essential point of this reform is based on the idea of permitting Mr Chavez to continue in power indefinitely," Miquilena told a news conference.
The 88-year-old former labour leader once was commonly referred to as Chavez's closest adviser. But he quit his cabinet in 2002 and has periodically criticised the president since.
The National Assembly has been firmly pro-Chavez since the opposition boycotted a 2005 vote.
The reforms, if approved, would extend presidential terms from six to seven years and allow Chavez to run again in 2013.
Chavez has said he could serve until 2021 or beyond, but only if the public continues to back him at the ballot box.
Chavez, who was re-elected by a wide margin in December on promises to steer the country towards socialism, says the changes will give Venezuelans greater decision-making power and aid the transfer of billions of dollars into social programmes from the country's foreign reserves.
Ismael Garcia, one of the assembly's few dissidents, criticised pro-Chavez legislators for excluding opposition groups from the discussion, arguing that Venezuelans of all political leanings must be included in the debate before the proposed reforms are put to a national vote.
Garcia said issues "such as the economic path of a new society" must be discussed. "This isn't just any debate," he said.
Other reforms would create new types of property to be managed by co-operatives, give neighbourhood-based "communal councils" administrative responsibilities usually reserved for elected officials and create "a popular militia" that would form part of the military.
The workday would also be reduced to six hours.