Johnson Muthama will not defend his Machakos Senator seat in the general election and has turned his focus to campaigns for NASA flag bearer Raila Odinga.
Wiper party, which is led by NASA vice president candidate Kalonzo Musyoka, did not hold nominations for the position. The Senator is a member of the party. He did not say whether he will quit.
Muthama cited massive irregularities and injustice in the party, saying only the chosen few were given tickets.
"I regret the way Wiper is being micro-managed to the disadvantage of some party members. My decision was influenced by the way Wiper affairs are being conducted," he told a press conference on Monday.
"I am ready to sacrifice my bid and continue serving the people outside of an elective position."
Muthama said he will not campaign anywhere for Wiper.
"As I contemplate my next move, I assure there will be a bruising political battle in Ukambani and that the voice of the people will be heard," he said.
"I do not feel that I have the face, anymore, to campaign or face out supporters of Wiper all over because the party has betrayed the people's trust, just like it did in 2013, by [imposing] Governor Alfred Mutua on the people."
The Senator noted the issuance of direct tickets to some aspirants blocked voters from exercising their right and caused many to go independent.
"Makueni Governor Kivutha Kibwana and CCU leader Wavinya Ndeti were given tickets while others were left to go through nominations which were marred by irregularities," he said.
He also gave the example of Kitui, whose Governor Julius Malombe faced Senator David Musila, who has now opted out of the party.
Muthama also said ballot papers were marked at Gracia Hotel on Friday, a day before the Machakos governor nominations were repeated, "in a bid for ensure Ndeti defeated Deputy Governor Bernard Kiala".
Ndeti initially defeated Kiala with 299,312 votes against his 4,663 but the DG raised several complaints and obtained a court order barring the party from conducting the primaries.
She defeated him again with 227,947 votes when the nominations were repeated on Saturday. Kiala, who caused drama at Gracia by trying to stop the dispatch of material, only got 4,508 votes.