Jakarta, July 25 (DPA) Indonesia's General Elections commission Saturday declared President Susilo Bambang Yudhoyono the winner of this month's presidential election, but his rivals vowed to challenge the conduct of the polls, citing irregularities in the voter rolls.

Yudhoyono won the July 8 election with 60.8 percent of the vote, said Andi Nurpati, a commission member who announced the final official vote tabulations.

His rivals, former president Megawati Sukarnoputri and outgoing Vice President Jusuf Kalla, had 26.8 percent and 12.4 percent of the vote, respectively.

Yudhoyono's landslide victory meant there was no need for a run-off.

Yudhoyono and Kalla signed the vote tabulation documents at the commission's headquarters, where police barricades had been erected and armoured vehicles were on standby in case of violent protests by rival supporters.

But Megawati refused to appear in protest of what her campaign team called 'legal flaws' in the conduct of the election.

A spokesman for Kalla's campaign team, Burhanuddin Napitupulu, said it would file a suit at the Constitutional Court Monday, saying there had been irregularities in the voter rolls, including duplicate names, that had prevented millions from casting their ballots.

'We accept the results but not the process,' he said.

A lawyer for Megawati, Gayus Lumbuun, said her campaign team would also challenge the results at the Constitutional Court for similar reasons.

Independent experts have criticised the election commission for failing to address problems in the voter list.