Two of Nigeria's 18 opposition parties have backed down on their earlier threat to withdraw from Saturday's presidential ballot. For VOA, Gilbert da Costa reports that cracks have emerged within the ranks of the opposition over the boycott threat and the nomination of a single opposition candidate.

A Nigerian stands near a poster with the picture of Muhammadu Buhari, a presidential candidate of the All Nigerian People's Party (ANPP), in Kano, 19 Apr 2007

Nigeria's main opposition party, the All Nigeria Peoples Party says it will participate in the ballot, breaking ranks with other opposition parties.

The Action Congress, another leading opposition party, which supports the candidacy of Vice President Atiku Abubakar, is also set to be part of the crucial vote.

University of Abuja political science teacher Usman Mohammed says the opposition's best option lies in forging a strong coalition.

"To boycott the election is very extreme," he said. "But, they can come up with extreme measures in order to safeguard what has happened."

With two of the leading opposition candidates opting to participate in the vote, the opposition is clearly split. Talks of nominating a single opposition candidate have disappeared, even as some opposition leaders met to salvage what is left of the coalition.

Other opposition parties insist on an election boycott.

"We are of the opinion that rather than the ruling party, in collaboration with INEC [Independent National Electoral Commission], bringing out the military from the barracks, bringing out the police to aid rigging of elections, we are saying that it will be better for the political parties to stay off from participating," said Kassim Afeagbu, a representative of the National Democratic Party.

"It will score us better than going to participate, when you know the outcome is predetermined," he added.

An 18-party coalition announced last Tuesday that it may not contest Saturday's ballot because it feared the vote would be rigged in favor of the ruling party.

The government has rejected the accusations and vowed to proceed with the weekend election, despite the boycott threat.

Under Nigeria's constitution, elections must be held by April 21, a month before the constitutional handover date of May 29.