In Venezuela, preparations are under way for a recall referendum Sunday to determine if President Hugo Chavez should leave office. Opponents of the controversial leader are expressing confidence that their effort will succeed. But Chavez supporters are bolstered by polls showing a tight race.

There is a tense calm in Caracas as the hour of voting draws near. Signs urging voters to either vote yes or no on the recall are plastered over walls and lampposts all over the city.

Both sides say they expect victory in Sunday's voting, but pollsters say it is too close to call. President Chavez has expressed confidence that the move to remove him will fail, but he has also said he will turn over power to the vice president if he loses the referendum Sunday and then run again for the presidency next month.

The president of the Venezuelan Electoral Council, Francisco Carrasquero, says he is prepared for a tranquil electoral exercise. He says he hopes all Venezuelans who are eligible to vote will carry out their constitutional right in an atmosphere of peace and order. He also called on Venezuelans to put differences aside once the votes have been counted.

Mr. Carrasquero met Friday with some of the foreign observers who have come to Venezuela for the referendum. Opposition leaders have expressed concern that government-imposed limitations on foreign observers may make it difficult for them to guarantee the integrity of the process.

Secretary-General of the Organization of American States Cesar Gaviria arrived in Caracas Friday expressing confidence in the Venezuelan electoral process. He said he believes the results of Sunday's referendum will be credible.

The recall referendum will culminate more than two years of efforts by opponents of Mr. Chavez to remove him from power by constitutional means. They accuse him of trying to establish a socialist state modeled on that of communist Cuba. A group of military officers carried out a coup d'etat against President Chavez in April, 2002, but his supporters took to the streets and succeeded in having him returned to power within less than 48 hours.

Since that time, Venezuela has remained deeply divided between the mostly poor sectors who support Mr. Chavez and the mostly middle and upper class groups who oppose him.

The Venezuelan president has called his opponents oligarchs and coup mongers, who want to re-establish the corrupt ways of the past. He has also accused the United States of trying to undermine his government.