Presidential candidate Raila Odinga has said he will contest his challenger Uhuru Kenyatta's win in court.
Mr Odinga pointed to problems in tallying the votes and urged his supporters to remain calm as he seeks relief from the Supreme Court.
"Raila has no intention of conceding and will be challenging this in court," Mr Odinga's advisor Salim Lone told the Nation.
"The level of the failures in the system makes it very difficult to believe it was a credible result, and if Uhuru is declared president, Raila will go to court."
Mr Lone said that Mr Odinga would “very strongly ask people to stay calm” and wait for the courts to address his complaints.
Mr Kenyatta garnered 6,173,433 votes out of 12,338,667 total votes cast in the March 4 General Election. This translates to 50.03 of the vote.
Mr Odinga came second after polling 5,340,546 which represents 43.28 per cent of the vote.
ODM's secretary general Anyang' Nyong'o told South Africa's Mail and Guardian Online that the party would file a petition at the Supreme Court "because the process has been awful and there's evidence to that effect".
On Thursday, the Coalition for Reforms and Democracy (Cord) demanded a stop to the vote tallying saying its integrity is "in question".
Kalonzo Musyoka, who was the running mate of Raila Odinga, said the Independent Electoral and Boundaries Commission (IEBC) should take the blame for the flawed vote count.
"We as a coalition take the position that the national vote tallying process lacks integrity and has to be stopped and restarted using primary documents from the polling stations," said Mr Musyoka.
He, however, told supporters to remain calm.
"This is not a call to mass action."
After the declaration of presidential results, the Supreme Court has 14 days within which it is required to rule on any petition challenging the results.