Venezuela's controversial new constituent assembly has overwhelmingly voted in favour of assuming the powers of the opposition-led parliament.
The move has been rejected by parliament, which said Venezuelans and the international community would not recognise the new powers.
President Nicolas Maduro says the new assembly will end the deadly political unrest in the country.
But many have called it a slide towards dictatorship.
The head of the Organization of American States (OAS) Luis Almagro called the move an "illegitimate dissolution" of the elected parliament.
Regional economic bloc Mercosur - which includes the region's two biggest economies Brazil and Argentina - also condemned the move and said it would not recognise the new assembly's actions.
Mercosur suspended Venezuela indefinitely earlier this month, urging Mr Maduro to release prisoners and begin a political transition.
Meanwhile the heads of the parliament and the new assembly have been trading insults on social media.
Parliament head Julio Borges accused the new assembly of a "coup" while new assembly head Delcy Rodriguez - a close ally of Mr Maduro - denounced his "lies".
Mr Maduro's wife and son are among the 545 members of the new assembly, which was set up following a controversial election earlier this month.
More than 120 people have been killed in violent protests since April.
The president's opponents want to hold a vote to remove him, blaming his left-wing administration for food shortages and soaring inflation in the oil-rich country.