He said Fayemi should have resigned his position as minister before the primary election took place.
Fayemi won the party's primary election on May 12, 2018, while he was still the Minister of Mines and Steel Development, a position he didn't officially resign from until May 30.
According to Oni, who polled second in the primary election, Fayemi should have resigned his position as minister before the election took place.
According to a report by TheCable, Oni has asked the court to determine if Fayemi's action did not violate the Nigerian constitution and the guidelines of the ruling party.
In the suit his lawyer, Gani Faniyi, filed at a federal high court in Abuja, Oni said Fayemi should have resigned at least 30 days to the primary election.
The suit read, "Whether by virtue of All Progressives' Congress constitution and particularly Articles 2 and 5 of All Progressives' Congress 2014 Guidelines for the nomination of candidates for public office as applicable to the APC Governorship primaries conducted on the 12th May, 2018, the 1st Defendant being a serving member of the Federal Executive and Federal Minister of Solid Minerals, Mines and Steel Development having not resigned his appointment as a member of Federal Executive and Minister of Solid Mineral, Mines and Steel Development, at all or at least 30 days to the said primaries election of 12th May, 2018 was qualified to contest and participate in the said All Progressive Congress Governorship primaries of 12th May, 2018 as an aspirant in that election.
"Whether by virtue of All Progressive Congress Constitution and particularly Articles 2 and 5 of All Progressive Congress 2014 Guidelines for the nomination of candidates for public office as applicable to the APC Governorship primaries conducted on the 12th May, 2018, at Damilek Event Centre, Ado-Ekiti for the purpose of determining or nominating the 2nd Defendant candidate for the 12th July Ekiti State Governorship election, the 1st Defendant having being indicted by Rtd. Hon. Justice Oyewole Judicial Panel of Enquiry was qualified to contest and participate in the said All Progressives Congress Governorship primary of 12th May, 2018 as an aspirant in that election."
Oni prayed to the court to declare him the valid flag bearer of the party in the upcoming election by virtue of polling second in the disputed primary election with 481 to Fayemi's 941.
He said, "A declaration that the claimant (Oni) having scored 481 votes which is the majority of lawful and valid votes at the 2nd Defendant (APC) the 12th May, 2018 APC Governorship primaries election for the purpose of determining the 2nd Defendant's candidate for the 14th July 2018 election for the office of Governor Ekiti State is the person that was validly nominated by the 2nd Defendant for the 14th July, 2018 election for the office of Governor, Ekiti state."
Oni has denied filing any lawsuit in court to invalidate Fayemi's primary election victory and blamed the opposition for the confusion.
The July 14 election is expected to be a straight battle between Fayemi and and current governor, Ayodele Fayose's deputy, Prof. Kolapo Olusola of the People's Democratic Party (PDP).
Fayemi was Ekiti state governor between 2010 and 2014 before he was defeated by Fayose during his re-election attempt.