The top challenger in Kenya's December 27 national elections, Raila Odinga, has widened his lead over incumbent President Mwai Kibaki, according to the latest opinion poll. Derek Kilner has more for VOA from Nairobi.

The new survey released by the Steadman Group firm shows Raila Odinga, of the opposition Orange Democratic Movement, leading incumbent President Mwai Kibaki, the Party of National Unity candidate, by 46 percentage points to 42.

Odinga has been ahead in most opinion polls since late September, but in the previous Steadman poll from two weeks ago, President Kibaki had narrowed the gap to three-tenths of a percentage point. A third candidate, Kalonzo Musyoka, received 10 points in the latest survey.

The new poll follows another survey, by Infotrak Harris, suggesting that a majority of Kenyan voters are skeptical that elections will be free and fair. Odinga supporters were much more likely to doubt the fairness of the vote.

Political analyst Mutahi Ngunyi says there is a genuine fear among many Kenyans that the elections could be rigged.

"The skepticism is completely serious in my view and this is because incumbent presidents in Africa do not lose elections unless they are incompetent," said Ngunyi. "When the election is so tightly contested, as this one will be, the incumbent will have to use every means available to them to make sure that they win, including rigging. In my view then, the fear of rigging is very high and as Kenyans we expect it. If Raila Odinga was winning in a landslide that would not be a fear."

The Steadman poll does not provide a margin of error and many observers say the presidential race is too close to call. Ngunyi believes there is also a strong possibility that the third-place Musyoka, eying the next election in 2012, could throw his support to the President in the run-up to the poll. That could hand the president enough of a boost to win the race.

The opposition's lead in legislative races, however, appears more secure. According to the Steadman survey, Odinga's Orange Democratic Movement is ahead of President Kibaki's Party of National Unity by a margin of 46 to 34 percentage points. A plausible scenario, then, would see Mr. Kibaki winning re-election but with a parliament controlled by the opposition.

Ngunyi says that under such a scenario, the opposition could call for new elections if they judge the vote was unfair. But he says a Kibaki victory is more likely to be followed by defections from the opposition.

"There are people within the ODM rank who will defect to government if Kibaki wins," said Ngunyi. "And this is also built around history. So if they cross over to government, then they will take the thunder away from the ODM project."

President Kibaki and Mr. Odinga are former political allies, but they split over a constitutional referendum proposed by the President in 2005. Odinga's Orange Democratic Movement first emerged during the campaign against that referendum, when a "no" vote was symbolized by an orange. The referendum lost and the opposition movement has been able to maintain much of the momentum it gained during that campaign.

The President is campaigning on his first-term achievements, which include a record of strong economic growth and the introduction of free primary education.

Odinga has accused the President of favoring his Kikuyu tribe - Kenya's largest - over other ethnic groups and of failing to follow through on a 2002 campaign pledge to combat corruption. Odinga also supports increasing government decentralization.

Support for parties, however, has generally been determined less by ideological sympathies and more by ethnic and regional affiliations.