CARACAS, Venezuela—Venezuela‘s Supreme Court has assumed all powers of the opposition-controlled congress, a move lawyers and rights activists said amounted to the effective dissolution of the legislature in Latin America’s largest oil producer.

“This ruling marks the point of no return for the dictatorship,” National Assembly Vice President Freddy Guevara said. Assembly President Julio Borges called the act a coup and urged Venezuelans to rally on Saturday to defend the country’s democracy.

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