VILLAHERMOSA, Mexico (AP) - Claiming fraud, opposition party members held a peaceful march Sunday, saying they wouldn't accept elections results in the disputed race for governor of the oil-rich Gulf state of Tabasco.
The march came hours before state election officials were expected to announce official results - and the winner of the gubernatorial race.
After the election a week ago, ruling party candidate Manuel Andrade had a slight 44 percent to 43 percent lead over opposition candidate Raul Ojeda of Democratic Revolution.
The results were too close to declare a winner, elections officials said.
The Tabasco election is an important test for Mexico's ruling Institutional Revolutionary Party, or PRI, which recently suffered its first-ever presidential loss since its creation in 1929.
Vicente Fox of the National Action Party will be sworn in as president Dec. 1.
The Tabasco race has been seen as an indicator of the PRI's ability to halt a possible collapse. The party, which never admitted losing any statewide race before 1989, has lost several gubernatorial races in recent years, most recently in neighboring Chiapas.
The loss set off a battle for control of the PRI, which has been dominated by the nation's president since the early 1930s.
A favorite for the leadership is outgoing Tabasco Gov. Roberto Madrazo, who has hoped to use the election here as a demonstration of his popularity.
Yet observer groups and opposition parties have charged that the Tabasco elections were stained by the sort of irregularities and fraud common in the PRI-dominated elections of Mexico's past, and many blame Madrazo.
Madrazo has denied the allegations, saying Andrade is the true winner.
At a rally Saturday, Ojeda said Vicente Fox should recognize his victory.
''We call on Vicente Fox to comply with his promise to guarantee democracy in the entire country,'' he told a cheering crowd.
Yet even after days of reviewing ballots, there were doubts the final count would be completely accurate. One electoral adviser, Joaquin Diaz, said he would not validate the results and called on other election advisers to do the same.
''I have many doubts, and I don't believe that I - or the rest of the advisers - have the instruments necessary to certify the results,'' he said, adding that he thought federal election officials should step in.
Floricel Medina, local director of the PRI, criticized Diaz, saying: ''His arguments are not reason enough to annul the will of the people. It's a personal opinion.''
Diaz accused the president of Tabasco's electoral institute of favoring the PRI and pressuring election officials to close the preliminary results early to benefit Andrade.
Election officials denied the accusations, saying they reviewed each ballot. ''The results are valid,'' spokesman Marco Dominguez said.