NIGERIA’S opposition parties have renewed calls for the result of Saturday’s presidential election to be overturned.

“We won the election and we will prove it to Nigerians,” third-placed Labour Party candidate Peter Obi said at a news conference in the capital Abuja on Thursday.

Mr Obi said that the election  had been marred by irregularities and would be remembered as one of the most controversial in Nigeria’s history.

Hours later, second-placed candidate Atiku Abubakar, of the People’s Democratic Party, also rejected defeat and said that he was consulting his lawyers on how to challenge the outcome.

“I have come to the conclusion that the processes and outcome of the presidential and National Assembly election of last Saturday were grossly flawed in every [way] and as such must be challenged,” he told another Abuja press conference.

At least four other parties are joining them in challenging the results.

However, an election can be invalidated only if it is proven that the national electoral body largely failed to follow the law and acted in ways that could have changed the result.

Bola Tinubu of the ruling All Progressives Congress Party was declared the winner and is scheduled to take office on May 29.