Venezuela was plunged into further political turmoil today as a constituent assembly dominated by supporters of President Hugo Chavez moved toward stripping the opposition-led Congress of its few residual powers and assuming control of current legislative affairs.

The 131-member assembly took up the matter in an emergency session this afternoon, five days after the recently installed body issued a decree that barred Congress from passing new laws and severely limited its other legislative functions. But lawmakers have defied the order and in doing so threatened to withhold approval for two foreign trips Chavez was to make, suspend corruption investigations and block budget appropriations totaling nearly $4 billion.

On Friday, street clashes erupted outside the Congress building between supporters and opponents of the president as lawmakers scaled fences and pushed their way through national guard troops to try to hold a special session. An agreement brokered by the Roman Catholic Church to seek a peaceful solution to the impasse has since unraveled.

The members of Congress "are simply taking obstructive measures because they can, and we are not going to put up with that," Luis Miquilena, president of the constituent assembly, said in an interview before the special session. But Mireya Rodriguez, head of a congressional faction opposed to Chavez, declared: "This is a coup d'etat. It represents the illegal concentration of power in Chavez and the assembly, which are the same thing. Democracy is dying in Venezuela."

On his weekly radio program today, Chavez--a radical populist who has promised sweeping political reforms--denounced the fact that a key congressional steering committee had vowed to prevent him from attending the inauguration Wednesday of Panama's president and a meeting next Saturday in Brazil with President Fernando Henrique Cardoso.

"If Congress does not even want to accept a request for me to leave the country, the constituent assembly will do it, without a doubt," Chavez said, adding: "We aren't going to raise the flag of tyranny or arbitrariness or persecution . . . [but] those who robbed the country are putting themselves on the wrong side of the rule of law, and the assembly will have to put order in that situation."

A draft decree introduced at today's special session stipulates that the assembly--which was elected in July under the mandate of a national referendum--would assume the functions of the steering committee should it delay or fail to carry out its duties. The decree would also require the country's state legislatures to operate through small steering committees, while the remaining members "cease their functions." Separately, the assembly is discussing the imposition of restrictions on state governors.

The assembly adjourned this evening on a point of procedure, but is scheduled to consider the decree again on Monday, and analysts say passage is all but certain.

Critics here have argued that the assembly's move in effect to shut down Congress is an anti-democratic maneuver and another step toward consolidating power in the hands of Chavez, 45, a cashiered army lieutenant colonel who led a failed coup in 1992. The Clinton administration has also expressed concerns about developments in Venezuela, one of Latin America's oldest democracies and one of the leading suppliers of oil to the United States.

"The democracy that is fighting for its life is dear to us," declared Virgilio Avila Vivas, one of five opposition members in the assembly, at today's special session. "Venezuelans have been born, raised and lived in democracy and that must continue. Changes must be made cleanly and in peace [to maintain] an equilibrium between powers."

Last Tuesday, Supreme Court President Cecilia Sosa resigned in protest after the court backed an assembly decision to give itself powers to fire judges and overhaul the country's judicial system. "The court simply committed suicide to avoid being assassinated," Sosa said. "But the result is the same. It is dead."

The assembly was created to rewrite the country's constitution, but Chavez has insisted that it has broader powers, which include restructuring and abolishing corrupt and inefficient public institutions. Assembly decrees covering Congress could remain in effect until new legislative elections are held next year.

Chavez, a fiery orator who promised a "peaceful revolution," won election by a landslide last year on a wave of widespread discontent over entrenched corruption in this oil-rich but poverty-stricken nation of 23 million. His ascendancy ended 40 years of domination by Venezuela's two main parties, which were largely controlled by the country's economic and political establishment.