Nigerian President Muhammadu Buhari looks set for re-election, results from Saturday’s general election show.
With results in from most states, he has a lead of more than three million votes over his rival Atiku Abubakar.
Mr Abubakar’s People’s Democratic Party (PDP) has called for a halt in the count, alleging irregularities.
Delays and violence marred the run-up to the vote but no independent observer has said that there was electoral fraud.
Mr Buhari, a member of the governing All Progressives Congress (APC) party, is seeking a second term in office.
So far the APC has 19 states, while the PDP has 16 plus the capital Abuja. The candidate with the most votes is declared the winner as long as they have at least 25% of the votes in 24 or more of the 36 states.
Each party says the other is working with the Independent National Electoral Commission (Inec) to influence the vote, which was initially scheduled for 16 February but delayed for a week at the last minute.
Mr Buhari has promised to build on his accomplishments in office so far, while Mr Abubakar, a business tycoon, has accused the president of wasting his term.
Whoever wins in Africa’s most populous nation and largest economy faces a range of problems including power shortages, corruption, security threats, and an economic slowdown.
The election commission is due to formally announce the winner on Wednesday.