Venezuelan Constituent Assembly delegate and leader of Venezuela’s ruling socialist party Diosdado Cabello, center, accompanied by fellow delegate Pedro Carreno, left, leaves the General Prosecutor’s office in Caracas on Aug. 16. Cabello is alleging that the husband and close aides of ousted chief prosecutor Luisa Ortega ran a multimillion-dollar extortion ring. (Ariana Cubillos/AP)

Venezuela’s new pro-government Constituent Assembly formally moved Friday to assume the powers of the opposition-dominated congress, completing what critics call a power grab that effectively puts all branches of government under the control of President ­Nicolás Maduro.

The Constituent Assembly, created in a July 30 vote decried as fraud by the opposition and a host of nations, had begun to assume the role of the National Assembly, whose members were democratically elected in 2015.

But in a move likely to spark further international condemnation, the motion Friday formalized the arrangement. The body was also poised to pass a new law that critics say could be used to punish opposition leaders and anti-government protesters with as much as 25 years in prison.

The body had invited the National Assembly to attend Friday’s session — an invitation that was declined. Before the vote to assume their powers, the Constituent Assembly’s president, Delcy Rodríguez — a top Maduro ally — theatrically pointed to the empty seats reserved for them.

“When they’re called for national dialogue, cameras please, see? Empty seats, There’s the definition of the Venezuelan right,” she said.

The opposition-led congress decried the vote as an attempt to finally “close” congress and said via its official Twitter account that it does not recognize the “fraudulent” move. It called on Venezuelans to join legislators in a session at the legislative palace, where the Constituent Assembly is convening, Saturday morning.

“The Constituent Assembly is null, and its acts are illegal and unconstitutional. The National Assembly, the international community and the people will not abide by the annulment decision,” the opposition tweeted.

Luis Almagro, secretary general of the Organization of American States, tweeted, “Fraudulent dissolution of the National Assembly by the Constituent Assembly deepens the coup d’état in Venezuela.”

But Diosdado Cabello, a senior member of Maduro’s inner circle, said that the decision had stopped short of disbanding congress and that the assembly was simply assuming congressional powers.

“For those raving, the Constituent Assembly has not eliminated the National Assembly,” Cabello tweeted. “It is only assuming the functions of those who have placed themselves on the margins of the constitution.”

Nevertheless, Venezuela’s congress appeared to be left in an even more precarious legal limbo. The pro-government supreme court robbed the congress of its authority in March. Yet even after the new Constituent Assembly began to meet in its legislative palace this month, opposition lawmakers have continued to convene there in a separate chamber. It remained unclear whether opposition leaders could continue that arrangement.

Maduro — the anointed successor of Hugo Chávez, who died in 2013 — has billed the Constituent Assembly as the cornerstone of his completing Chavez’s socialist dream. The assembly’s members — ranging from student leaders to fishermen to top government officials — are being vested with vast powers to change the constitution, and will be used to streamline efforts to funnel more power and authority to local communities. But critics say that in practice it will be used to consolidate Maduro’s power and ensure more political largesse in poor communities in exchange for their loyalty.

The U.S. Department of State condemned the move Friday evening.

“The United States strongly condemns the assumption of legislative powers by the illegitimate Constituent Assembly,” a State Department news release said. “This power grab is designed to supplant the democratically-elected National Assembly with an authoritarian committee operating above the law. In our view, the democratically-elected National Assembly is the only legitimate legislative body. … As long as the Maduro regime continues to conduct itself as an authoritarian dictatorship, we are prepared to bring the full weight of American economic and diplomatic power to bear in support of the Venezuelan people as they seek to restore their democracy.”

The moves come amid an escalating crackdown on dissent after four months of anti-government street protests have left more than 100 dead.

The Constituent Assembly moved Thursday night to strip legislative immunity from ­Germán Ferrer, a member of the elected congress. It came as he and his wife, Luisa Ortega Díaz — Venezuela’s former chief prosecutor who was removed from office this month — appeared to join a rising number of dissidents fleeing the country to escape a broadening crackdown.

On Wednesday, the supreme court issued an arrest order for Ferrer. Both he and Ortega were previous government loyalists who turned against Maduro amid mounting allegations of human rights abuses and corruption. They had emerged as two of the most vocal and influential government critics.

Nicmer Evans, a political ally of the couple, told The Washington Post that they had left Venezuela.

Late Friday, Colombia’s immigration agency confirmed that Ortega and Ferrer had arrived in Bogota via a private flight from Aruba. In the afternoon, Ortega participated via a video call in a meeting with top prosecutors from across Latin America. She said she had proof that Maduro and his circle were involved in the Odebrecht corruption scandal, that her removal was the “materialization of the systematic persecution” against her and her office, and that the new chief prosecutor’s office would destroy any evidence that came his way.

“I will not stop fighting. And I ask you to not abandon Venezuela,” she said.

Since the Constituent Assembly’s creation, three opposition mayors have gone into hiding, and two have fled the country.

Addressing the increased targeting of dissenters, opposition lawmakers said in a statement that “Nicolás Maduro needs silence to consummate injustice. Any expression of the people’s voice is being criminalized.”

The arrest warrant for Ferrer was connected to government charges that had used his wife’s former post to extort $6 million from business executives. Ferrer has strongly denied the charges, describing them as political persecution.

In an interview with The Washington Post this month, Ortega denounced the creation of the Constituent Assembly — members of which include Maduro’s wife and son — as “the birth of a dictatorship.”

“We are just a tiny sample of what comes to anyone who dares to oppose the totalitarian way of governing,” she said. “I will continue fighting for Venezuelans, for their liberties and rights, until my last breath.”

Faiola reported from Miami.