The National Election Committee has said it will not stop using a voter registration system that smaller parties say gives the ruling party and edge.
Current regulations include a registration and identification process that makes voting hard for displaced persons or those who have moved around, smaller parties say.
Since these people are often the disenfranchised who might vote for change, opposition politicians have pushed for a change in the law.
The head of the NEC said Wednesday he would not follow a request from the Sam Rainsy Party to change the regulations.