Nigeria's former military ruler, Gen Olusegun Obasanjo, was certain to regain power he relinquished 20 years ago after most presidential election results were announced yesterday.
But his opponent, Mr Olu Falae, disputed results which showed him nearly seven million votes behind after 27.5 million ballot papers had been counted from 33 of Nigeria's 36 states.
Foreign observers expressed serious concerns about rigging at the ballot on Saturday, but singled out neither camp as particular cheats. The election is intended to end 15 years of crippling military rule in Africa's most populous nation.
"I said if Gen Obasanjo won a free and fair election I would congratulate him, but clearly this is not a free and fair election," Mr Falae said in his hometown of Akure.
Supporters of Gen Obasanjo made their way to the capital, Abuja, to prepare for the official announcement. They also set about discussing their next moves in preparation for May 29th, the date on which the current military ruler, Gen Abdulsalami Abubakar, has pledged to step down. The Independent National Electoral Commission said the winner would be formally announced today.
The turnout appeared to be slightly higher than the 50 per cent of an estimated 40 million voters recorded at previous ballots. They were participating in the latest of many attempts to break the hold of the military in the oil-producing country of 108 million people.
But international observers expressed concern. "There were some disparities noted by ourselves - my wife and I - and also by members of our delegation yesterday," said former US president Jimmy Carter, who jointly led an American delegation of observers.
"Some of the local officials apparently permitted exaggerated reports of voter participation, and in some cases that we witnessed there were some ballots in the box that were not cast by voters."
However, a spokesman for the electoral commission said the two parties had representatives at polling stations who had signed their agreement with the results.
Foreign approval for the election is essential for Nigeria, which is trying to regain world respect after years of human rights abuses and corruption.
Mr Carter said irregularities could affect the result only if it was a close call. But that became impossible after the lead taken by Gen Obasanjo in all areas but the ethnic Yoruba south-west, a homeland he shares with Mr Falae and Moshood Abiola, the presumed winner of the annulled 1993 elections, who died in detention last year.
The need to appease Yoruba sensibilities was behind the decision to put up candidates from their region in the election, which marks a power shift from the conservative Muslim Hausa-speaking north.
Despite Mr Falae's fighting words, the mood in his hometown was more of resignation than defiance. "I support Falae but if the results show Obasanjo has won then so be it," said Mr Ezekiel Adetunji, one of his activists.
Gen Obasanjo did particularly well in the north, which has dominated Nigerian political life since independence from Britain in 1960. Policy issues played little role in the election, with both parties promising to revitalise Nigeria after embezzlement and mismanagement under a string of military rulers who have ruined the economy.
The vote fulfilled a promise by Gen Abubakar to restore democracy after he assumed power following the sudden death last June of the dictator Sani Abacha. Abacha had seized power in 1993 amid chaos following the annulment of elections Abiola was about to win. He detained both Gen Obasanjo and Mr Falae for opposing him.
Abiola died in prison a month after Abacha's death.