Former President Jimmy Carter arrived Friday to help lead a group of international observers monitoring elections Sunday amid government restrictions and fear of fraud by supporters of Gen. Manuel Antonio Noriega.

Carter, who along with former President Gerald Ford leads the team of 19 independent observers, flew to Panama on a flight from Georgia.Ford, who arrived Thursday, said the group would meet with representatives of pro- and anti-Noriega coalitions but would not issue a judgment on the elections until next week.

The government Electoral Tribunal has prohibited observers from being present when votes are counted and has banned publication or use of partial or unofficial results from exit polls or partial counts by independent observers.

"We are doing the best we can to proceed as an international observer delegation under numerous restrictions," said one organizer of the Ford-Carter trip.

Guillermo Endara, 53, candidate of the Civil Democratic Opposition Alliance coalition, leads the pro-Noriega candidate Carlos Duque, 59, of the coalition of parties known as COLINA, by 2-to-1 in independent polls.

But Duque campaign officials insist their polls indicate they will win a narrow victory, and both opposition leaders and foreign observers - including the Bush administration - have said they expect fraud.

Endara himself has said the government would try "massive fraud" to obtain a Duque victory and keep Noriega in power. Endara has said he would seek to get rid of Noriega if elected.

The winner takes office Aug. 1 and replaces acting President Manuel Solis Palma, chosen by Noriega in February 1988 to replace President Eric Delvalle - who was ousted for trying to fire Noriega as head of the 15,000-man Panama's Defense Forces. The United States continues to recognize Delvalle, living in exile in Miami, as Panama's president.

Besides the presidential race, slightly fewer than 1.2 million Panamanians will cast votes for two vice presidents, 67 deputies to the Legislative Assembly and representatives to 510 municipal councils.

Endara is the political heir of Arnulfo Arias, a populist politician cheated four times of victory in past presidential elections, either by fraud or by a military coup.

Duque is an associate of Noriega in several business ventures and has won praise for his loyalty from the military.

A poll by a respected Chilean political think tank showed 60.5 percent of Panamanians say they will vote for Endara and 19.4 percent said they prefer Duque.