Governor Okoth Obado and his rival Ochillo Ayacko have accused each other of sponsoring violence in the county.
Mr Obado, who spoke when the two appeared before the Independent Electoral and Boundaries Commission (IEBC) in Nairobi, said he had not played any role in the chaos witnessed in the county.
Obado, who is defending his seat on an ODM ticket, also accused the former assistant minister of defacing his campaign posters.
In his petition, Obado also wants Mr Ayacko to stop using National Super Alliance (NASA) presidential candidate Raila Odinga's portrait because he is an independent candidate.
"I am known for peaceful campaigns but it is a different year for me because of my opponent here. I am here to ask you to talk to my opponent and ask him to stop his supporters from engaging in violence. If my opponent is not contained, the violence in Migori may escalate beyond control," Obado said.
But Ayacko told the commission Obado was the one known for violence. He cited the Sh1 million ODM fined the governor for poll violence, stating that the governor had a history of causing chaos.
He also termed a fabrication claims that he was using banners bearing NASA colours and symbols.
"The banners issue is a fabrication of Obado's people to bring this case before you. The banner could have been made by his people. The governor's popularity is waning because people believe he stole the ODM nominations," said Ayacko.
The IEBC's Electoral Code of Conduct Enforcement Committee, under chairman Wafula Chebukati, fined Economic Empowerment Party parliamentary candidate for Makadara Robert Momanyi Sh250,000 for using Jubilee Party colours and symbols.
Mr Momanyi risks being disqualified if he fails to pay the fine. He is also expected to remove all his campaign materials bearing Jubilee symbols within 48 hours.
Meanwhile, Meru Woman Representative Florence Kajuju accused her opponent, Kawira Mwangaza, of using a local television station she has links with to distort her campaign messages.
Ms Kajuju wants IEBC to stop Baite TV from covering her political campaigns because it is reportedly owned by Ms Mwangaza's sister and mother.
Mr Chebukati said his team would make a ruling on the cases.
