The opposition in Nigeria has filed an appeal to overturn the election results.

Nigeria's opposition presidential candidate, Peter Obi, who finished third in last month's poll, has submitted an official appeal in court attempting to overturn the governing party candidate's ballot.

The Monday petition is expected to be the first step in a lengthy legal battle over the February 25 presidential election, as has occurred in previous presidential elections in Africa's most populous country.

Obi of the Labour Party was an unexpected third contender whose appeal to younger voters enabled him to challenge the governing All Progressive Congress (APC) and the major opposition Peoples Democratic Party's supremacy. (PDP).

Obi claims that the Independent National voting Commission, or INEC, violated voting legislation in a case submitted in an Abuja appeals court.

INEC has refuted any illegal action while admitting technical difficulties.

Among other things, the motion claims Tinubu is unqualified to run for office because of a drug-related forfeiture of nearly $500,000 from one of his funds in a US bank in the 1990s. Tinubu has denied all misconduct.

The ruling APC in Nigeria gained the majority of the states in the local elections, despite a poor participation.

"The election... was invalid due to corrupt practices and noncompliance with the provisions of the electoral act," according to the appeal.

It says "based on the valid votes cast", Obi gained the largest number and "ought to be declared the winner of the presidential election".

The major opposition presidential contender PDP's Atiku Abubakar has also said he will dispute the findings, labeling the election a "rape of democracy".

Analysts predict that those judicial challenges will wind up before the country's Supreme Court, as they did following the 2019 election.

After two terms, President Muhammadu Buhari will stand down in May, leaving Nigeria dealing with pervasive unrest, economic problems, and increasing poverty.

Nigerians had anticipated that the presidential election would allow them to be heard, but many were disappointed by how the election was handled.

International monitors, including those from the European Union, expressed concern about significant organizational issues, alienated electors, and a lack of openness.

"The process of reclaiming the people's mandate has begun," Yunusa Tanko, a Labour spokesperson, said in a statement on Tuesday.

Earlier in the day, President-elect Tinubu called for unity, adding that "the time for politicking is over."

- Physical coercion -

Following a ballot marred by voter suppression and violent threats, Nigeria's governing party also won the majority of governorships fought in last weekend's local elections, according to findings released Tuesday.

Governors and state legislature members were elected in 28 of Nigeria's 36 states. Governors in the remaining eight states were previously elected in by-elections.

"Many were disappointed, and we saw voter apathy, which is a clear result of failures by political elites and, sadly, also by INEC," -  Barry Andrews, EU mission Chief Observer