Deputy President William Ruto has now challenged Baringo residents to reject area senator Gideon Moi in Augusts elections.
The DP, backed Simon Chelugui who had unsuccessfully vied for governor in 2013 for the senatorial seat, a move that sparked heated political debate in the region.
Senator Moi, who also doubles as KANU national chairperson, has been critical of the DP and has openly accused him of dictating Rift Valley residents.
"You can only benefit when you carefully use your votes in an election. Do not scatter your votes because it is detrimental to do that," he told said during his Saturday's tour in Baringo.
"I want you to vote for Jubilee in all seats available. Will you vote a Jubilee senator? I want to be sure that you will give me a Jubilee senator," he added .
Mr. Moi was last week given a fortnight to settle on a presidential candidate to be backed by KANU, barely a week after Secretary General Nick Salat endorsed the opposition team under the leadership of Raila Odinga.