Leftist President Rafael Correa scored a major victory Sunday as Ecuadoreans voted overwhelmingly to support his ambitious plan to remake the nation's system of government and weaken its discredited Congress, an exit poll showed.

Voters across this small Andean nation, from highland Indians in ponchos to fishermen in villages along its Pacific coast, turned out to cast ballots on the need for a special assembly to rewrite the constitution — a measure many hope will bring economic improvements to their lives.

An exit poll by CEDATOS-Gallup showed 78.1 percent of voters approved the election of a constitutional assembly while 11.5 percent rejected the proposal and 10.4 spoiled their ballots or cast blank ones.

CEDATOS-Gallup said 2,000 pollsters interviewed 40,000 voters nationwide with a margin of error in the result of 2 percent. Official results will not be available for five days.

"We have defended and achieved the right to express ourselves in the ballot box and hopefully in the future all political players will acquire these democratic values," an optimistic Correa told reporters earlier Sunday.

Correa enjoys a 70 percent approval rating and polls predicted a majority would vote in favor of the referendum in a country long plagued by political instability and poverty.

Congress, which Correa has labeled "a sewer of corruption," has dismissed three presidents in the last decade, violating impeachment proceedings in the process.

"We have a presidential system in theory but in practice who runs things in this country is Congress. That can't be," Miguel Macias, a constitutional expert, said Sunday.

But critics fear Correa could wind up controlling the assembly and seeking dictatorial power. They are worried by what they call his increasingly authoritarian style — similar to his ally Hugo Chavez, the firebrand president of Venezuela.

Chavez, for his part, wished the Ecuadorean people the best of luck on Sunday and said Correa "has taken on 21st-century socialism and the call for a constituent assembly with courage and bravery."

Correa, 44, a political outsider with a doctorate in economics from the University of Illinois, won election in November as Ecuador's eighth president in 10 years with a power-to-the-people message, promising to clip the wings of Ecuador's political establishment.

Tall and charismatic, Correa has drawn big crowds with angry speeches, assailing his opponents and critics as corrupt. The more he attacks Ecuador's elite, the more his bond with Ecuador's poor majority appears to strengthen.

Correa has also been favored by Ecuador's oil-based economy. It is relatively stable thanks to high crude prices and the adoption of the U.S. dollar as Ecuador's official currency in 2000. But most Ecuadoreans remain poor and are increasingly demanding more from their government.

Correa has offered few details on the anti-corruption measures he envisions will result from a new constitution. But he said a new charter should eliminate the authority of Congress — which is controlled by Ecuador's traditional parties — to name judges and other judicial and electoral authorities.

Opponents fear he'll use the constituent assembly to consolidate enough power to overcome any opposition from other branches of government.

"The president is very intolerant of criticism and he is very hard on his opponents," said political scientist Simon Pachano. "It seems to me that there is a strategy of confrontation. The government is not looking for a consensus on political reforms."

During his campaign, Correa said he planned a heavy state role for Ecuador's free-market economy to divide wealth and benefit the country's poor majority. Since taking office in January, however, he has moved cautiously on economic reforms, saying he did not want to open more than one front at a time until his supporters win control of the constitutional assembly.

But Correa has begun to increase spending on social programs, including doubling welfare payments to $30 a month and expanding government loans for low-cost housing. He is financing the sharp increase in spending by making use of hundreds of millions of dollars in emergency reserve funds created by record-high oil prices.

Walter Spurrier, an economic analyst, said Ecuadoreans "see that he is taking steps to help lower-income people improve their economic situation thanks to all the subsidies."

Voters in the capital of Quito, 9,300 feet high in the Andes, turned out early, with most openly expressing support for Correa. To win, Correa's proposal must obtain 50 percent plus one vote of the 6.2 million ballots expected to be cast nationwide, including blank and spoiled ballots.

Entrenched business interests in Guayaquil, Ecuador's largest city, located on the muggy tropical coast, have been the most cautious in accepting Correa's leadership. Heavy spending on advertising by business groups opposed to the assembly created some doubts the referendum would pass with a wide margin.

But even here, members of the poor majority clearly favor reforming the political system.

Daisy Avila, 26, the single mother of two small children who works as a maid in a five-star hotel, supports Correa and his plans for a new constitution, hoping it will bring a better life for people like her. She makes only $140 a month on average, depending on the hotel's occupancy, and short-term contracts give her no job stability.

"Correa said he would put a stop to that with the assembly," she said. "I hope with all my heart that he wins."