The Independent National Electoral Commission declares Bola Tinubu winner of Nigeria's 2023 presidential elections in Abuja
Nigeria's newly declared winner of 2023 presidential election, Bola Tinubu speaks at the National Collation Centre in Abuja, Nigeria, March 1, 2023. Reuters

Six opposition-led Nigerian states have asked the Supreme Court to throw out the result of last weekend's presidential vote, saying the electoral body broke the law and its own rules during the count, court papers showed.

Ruling All Progressives Congress (APC) party candidate Bola Tinubu was declared the winner on Wednesday, but the two main opposition challengers said the result was fraudulent and vowed to challenge it in court.

Six of Nigeria's 36 states - Adamawa, Akwa Ibom, Bayelsa, Delta, Edo and Sokoto - said in court papers dated Feb. 28 that the election commission had failed to transmit results through an electronic system meant to show transparency.

They sought a court declaration that all presidential election results announced by the chairman of the Independent National Electoral Commission (INEC) "were invalid, null and void, and of no effect whatsoever".

There was no immediate comment on the case from the government, Tinubu's campaign council, the INEC or the Attorney General of Nigeria, Abubakar Malami, who was formally cited as respondent in the lawsuit.

The six states are led by governors from the main opposition People's Democratic Party, whose candidate Atiku Abubakar came second in the election, according to the official tally.

Separately, third place candidate Peter Obi late on Friday secured a court order granting his party access to electoral materials possessed by the INEC, to let it gather data for a possible legal challenge.

Those materials included ballot papers and voting machines, the order from the appeals court showed.

Obi still has three weeks to file a petition, under the 2022 electoral act.

Election observers from the European Union, the Commonwealth and other bodies reported a range of problems during voting and counting, including failures in systems designed to prevent vote manipulation.

The observers criticised the INEC for poor planning and voting delays but did not allege fraud. The commission apologised for technical problems during the count.

In Nigeria, elections are generally challenged at the Appeals Court, which sits as a tribunal.

But the six states sidestepped that process and sued the federal government, not the INEC, arguing that this was a constitutional case which falls within the jurisdiction of the highest court in Nigeria.

No date has been set for a hearing, according to the Supreme Court register.

There have been numerous legal challenges to the outcome of past Nigerian presidential elections but none has succeeded.