Kenya's opposition National Super Alliance (Nasa) has withdrawn from the repeat presidential election scheduled for October 26.
Nasa candidate Raila Odinga made the announcement at a press conference relayed live on television in Nairobi.
Mr Odinga was flanked by his running mate Kalonzo Musyoka and several members of their coalition.
“After deliberating on our position in respect of the upcoming election, considering the interests of the people of Kenya, the region and the world at large, we believe that all will be best served by Nasa vacating its presidential candidature in the election scheduled for 26 October 2017," said Mr Odinga.
He accused the Independent Electoral and Boundaries Commission (IEBC) of “stonewalling” deliberations to have a credible repeat presidential election.
“We have come to the conclusion that there is no intention from IEBC to make sure that the irregularities and illegalities witnessed before do not happen again,” he said.
He accused ruling Jubilee party of pushing for amendment to the election laws which "demonstrates that it has no intention of competition on a level playing field."
"The only election Jubilee administration is interested in is one that it must win, even unlawfully."
The repeat poll was expected to pit Mr Odinga and Mr Musyoka against President Uhuru Kenyatta and his deputy William Ruto.
The Supreme Court of Kenya on September 1 nullified the August 8 re-election of President Kenyatta and Mr Ruto.
The court cited mass irregularities and illegalities in the August poll.
Nasa also took a swipe at some "international actors" for siding with Jubilee.
"It is unfortunate that international actors who have supported Kenyans in their quest for democracy and good governance are now on the side of appeasing dictatorship in the mistaken belief that it will maintain stability," he said.