With just over a third of the votes counted from Monday's Indonesian election, the party of popular opposition leader Megawati Sukarnoputri maintained its strong lead as fresh concerns arose over possible cheating by the ruling Golkar party.

Golkar, the vehicle of the discredited Suharto regime, was a distant second as popular resentment over decades of misrule ate into its once-unassailable bloc of support. Golkar received 72 percent of the vote in the controlled election in 1997, but this time seems barely able to reach 20 percent with people voting freely, according to the partial returns.

Officials of Megawati's Indonesian Democratic Party of Struggle (PDI-P) remained confident today, with the party's vote ranging between 35 and 40 percent, according to the various tabulations. If that tally holds, the party will have the best chance to form a new governing coalition and to select the country's next president.

But party members' optimism was tempered by some new reports of election-day vote rigging by Golkar, which opponents claim may be bolstering its totals in its key stronghold of Sulawesi island, and also in Kalimantan.

In the North Sulawesi capital of Manado, 18 political parties demanded a new election after the tally showed Golkar winning with more than 800,000 votes compared with just over 100,000 for PDI-P -- a margin that many of the losing parties called too large to be credible. Some 600 people demonstrated there today against the alleged cheating.

And in South Sulawesi, the home region of incumbent president and Golkar candidate B.J. Habibie, 46 parties issued a rare joint call for the elections to be repeated, because of allegations that Golkar officials were using a tactic called "morning operations," in which village heads are given cash to distribute to voters on election day.

International election monitors have cautiously praised the success of the election, but did say there were a few problems to be investigated. "There were irregularities," said Mary E. Schwarz, program director of the International Republican Institute, which was monitoring the elections on Sulawesi. "Whether or not it's going to truly flip the balance of power, I think we have to wait until the numbers are in."

A Western diplomat speculated that local Golkar workers may have been trying to pad their winning margins in "safe" areas, to add to their seat total in the next parliament.