Kiambu Governor Ferdinand Waititu suffered a blow on Tuesday after an attempt by Majority Leader Kipchumba Murkomen to establish a committee to investigate his impeachment flopped.
Senator Murkomen had picked 11-member committee, most of them who were considered "friendly" to the embattled governor, a move which could not work.
Of those present, 28 voted against the move with only 16 supporting Murkomen.
Waititu is perceived as allied to DP William Ruto's camp.
This means that the impeachment of the governor proceedings at the Senate will be done on plenary, where all members shall participate.
"The Senate has rejected the motion seeking to establish an 11-member Committee – chaired by Sen @cleophasmalalah and deputized by @susankihika – to investigate the Proposed Removal from Office, by impeachment, of the Governor of Kiambu County. Investigation to be done in plenary," Senate noted in a tweet.
The idea to adopt plenary approach was suggested by Senator Amos Wako of Busia.
A number of senators claimed that there was an attempt to use the committee to save Waititu.
Earlier, Murkomen had asked the members whom he picked to diligently execute their duties in a period of ten days.
"I urge my colleagues who will be in this committee to uphold integrity, stick to the Law and table a report that holds the confidence of the people," he said.
Currently, Waititu is barred from stepping to his office over corruption allegations, forcing his deputy James Nyoro to take over.