The presidential election petition tribunal on Thursday continued hearing into an application challenging the election of President Muhammadu Buhari in the February 23 general elections.
The petition was brought by the Peoples Democratic Party and its presidential candidate, Atiku Abubakar.
Mr Buhari was declared winner of the election, making it possible for him to remain in office for a second term, having been first elected in 2015.
Apart from the application challenging Mr Buhari's emergence as winner of the 2019 elections, the PDP is also contesting the position of the President of the Court of Appeal, Zainab Bulkachuwa, as a member of the presidential election tribunal.
Mrs Bulkachuwa's husband, Adamu Bulkachuwa, was controversially selected by Mr Buhari's party, the All Progressives Congress, to contest for the position of a senator. He eventually won the election.
The PDP has alleged that the emergence of Mr Bulkachuwa as senator put Mrs Bulkachuwa in a questionable position with regards to the ongoing petition.
Mrs Bulkachuwa is expected to rule on the application challenging her position on the panel on Thursday.