Former Lugari MP Cyrus Jirongo is set to launch his presidential bid and party in Nairobi on Friday.
The United Democratic Party leader's move puts into jeopardy the quest for Luhya unity in NASA ahead of the August poll.
The entry of Jirongo makes him the third presidential candidate from Western Kenya after both ANC's Musalia Mudavadi and Ford Kenya's Moses Wetangula declared their interest.
UDP national organising secretary Charles Werangai said Jirongo's entry into the race is a bid to ensure Luhya community has a presidential candidate in the August poll.
“The feeling and agreement by Western leaders was that a Luhya must reach the ballot, but it appears there is going to be none after Mudavadi joined forces with Odinga’s ODM, Ford Kenya, and Wiper, where it is not certain a Luhya will have the ticket,” he said.
Jirongo had in 2013 tried to run for the presidency but stepped down at the last minute to back Raila Odinga.