The Sam Rainsy Party filed more than 17,000 documents as evidence of vote fraud to the Constitutional Council Tuesday, in the party's final appeal contesting the results of July's election.
The leading opposition party maintains that the results of the elections, in which the ruling Cambodian People's Party claims to have won 90 of 123 National Assembly seats, are not valid.
The party, which has claimed 26 seats, has called for a nationwide re-vote, joined by the Human Rights Party in a denial of the results.
The National Election Committee ruled earlier this month the election results should stand, and the Council now has between 10 and 20 days to determine whether a hearing is necessary for the complaint.
Opposition leader Sam Rainsy has said he will wait to hear the results before determining whether to attempt to deadlock the government by boycotting a National Assembly swearing-in ceremony next month.
The SRP complaint included more than 100 administrative forms, numbered 1018, which the party claims was used in lieu of photo identification to add votes to the CPP count.
"We have additional, new evidence to support our complaint to the Constitutional Council," SRP lawyer Kong Sam On told reporters Tuesday. "We have witnesses, witness reports, form 1018, and nearly 20,000 voter's with their names omitted [from registries]."
Opposition leader Sam Rainsy said Tuesday he had no faith in the Constitutional Council.
"We've come here for hopelessness," he said. "But we must follow the procedure."
The Council's decision was likely to serve the interest of the CPP only, he said.
The Council has denied two previous SRP appeals. The Council upheld a fine against the party for insulting CPP leaders, and denied a hearing on the validity of the 1018 forms for voter registration.