The APC said in a countersuit on Tuesday that losing candidate Peter Obi's petition should be dismissed on several grounds, including that Obi was not a Labor Party member when he contested the elections and that he failed to include People's Democratic Party's (PDP) Atiku Atiku as a respondent, making his petition "incompetent."
Obi, who came third in the election, and second-placed Abubakar last month separately challenged the results in court.
The two candidates said the results were fraudulent, citing Tinubu, his ruling All Progressives Congress Party (APC) and the Independent National Electoral Commission (INEC) as respondents.
The Appeals Court has yet to nominate judges who will constitute a tribunal to hear the presidential election petitions and deliver a verdict within 180 days from the date the court challenges were filed last month.
Obi, who was Atiku's running mate in 2019, left the PDP in May last year to join the Labor Party. The APC is arguing that Obi was not yet a member when Labor Party submitted its members register to the electoral commission as required by law.
The ruling party is yet to respond to Atiku's petition.
