Nigeria's main opposition leader Atiku Abubakar on Tuesday filed an appeal at the Supreme Court challenging a tribunal ruling that upheld President Bola Tinubu's victory in a February election, a court filing showed.
No legal challenge to the outcome of a presidential election has succeeded in Nigeria, which returned to democracy in 1999 after three decades of almost uninterrupted military rule.
Atiku, from the People's Democratic Party, said in his appeal that the tribunal erred in law "when it failed to nullify the presidential election... on the ground of non-compliance" with the electoral law.
A five-member tribunal had rejected the challenge by Atiku, who came second behind Tinubu and Peter Obi, of the Labour Party, who polled third in the presidential race.
The two opposition candidates had asked the tribunal to cancel the election, alleging irregularities.
