QUITO (AP) -- Ecuador's Congress approved holding a referendum on whether to create an assembly to rewrite the constitution, bowing to demands by the new leftist president who is seeking to weaken traditional political parties.

Rafael Correa, wants the assembly to rewrite the constitution to limit the power of the parties, which he blames for this small Andean nation's problems. "The fight is just starting," Correa said in a statement. He called on Ecuadorians "to fulfill their role in history, crushing the political mafias at the ballot boxes."

Ecuador has been marked by political instability, with seven presidents in the last decade. More than 60 percent of the population lives in poverty.

Correa, 43, who took office Jan. 15, won a November election runoff as a charismatic outsider who pledged to lead a "citizens' revolution" against a political establishment widely seen as corrupt and incompetent.

Opposition lawmakers, meanwhile, have raised fears that a constitutional assembly with unlimited powers, as Correa advocates, might move to close the legislature.

"We're going to have generalized chaos throughout the country starting tomorrow," said Federico Perez, the only congressman who voted against the measure. Earlier this month, Correa's government denied any plans to dissolve the legislative body, which the president has called a "sewer of corruption."

Correa has rejected accusations of authoritarianism and says his reforms aim to make elected officials more accountable.

Nearly 1,000 people gathered outside Congress, including hundreds of highland Indians in traditional clothing, to demand lawmakers approve the referendum.

The Supreme Electoral Tribunal later said the referendum would be held April 15.