Opposition parties in Nigeria’s fiercely contested polls will attempt to do what has been described as the impossible – getting a court to overturn the outcome of a presidential election in Africa’s most populous nation.

Peter Obi and Atiku Abubakar, the second and third-placed candidates in the tightest presidential election since the end of military rule in 1999, are heading to court to challenge the result that saw Bola Tinubu of the ruling party declared the winner with 37% of the vote.

While Mr Abubakar of the main opposition Peoples Democratic Party (PDP) called the result “a rape of democracy” after getting 29% of the vote, the Labour Party’s Mr Obi, who got 25%, told supporters they had been “robbed” of victory, and vowed to “prove it to Nigerians”.

All petitions challenging an election in Nigeria must be filed within 21 days of the announcement of the results or they will not be considered.