Kenya's Supreme Court has unanimously upheld President Uhuru Kenyatta's election victory in a rerun vote that was held in October.

Opposition candidate Raila Odinga had said the results of the first election were invalid and challenged the processes of the second vote - eventually pulling out of the second race.

Following Monday's ruling, opposition supporters are expected to hold rallies against it and Kenyatta is expected to be sworn on November 28.

"All six judges sitting on this case said that the petitions filed to the court to cancel the results of the rerun of the presidential election had no merit," Al Jazeera's Fahmida Miller, reporting from the capital Nairobi, said.

"Odinga has not said exactly until now what he will do after the ruling is announced. So far, they have started an economic boycott to protest the results," she added.

Riots and violence

Days of violence and protests against Kenyatta have led to deaths in Nairobi.

The opposition claims that authorities have been using "armed militia and live bullets" to disperse supporters.

October's repeat poll, which was boycotted by Odinga and won by Kenyatta with 98 percent of the votes, was ordered by the Supreme Court after it annulled the results of an August election over irregularities.

Kenyatta called the case against the rerun of the presidential election a waste of time.

Odinga, in return, vowed to embark on a political campaign in Kenya to "restore democracy in the country", and called for a "resistance movement" to protest against the results.