Migori Senator Wilfred Machage has decamped from the Orange Democratic Movement to the Democratic Party.
Dr Machage announced on Friday that he will leave the Senate to run for the Kuria West parliamentary seat seat on a DP ticket.
Dr Machage, however, declined to reveal if he had written to ODM, which sponsored him to the Senate, to notify the party of his departure.
"Those are details," Dr Machage said during a press conference in Nairobi.
He said parties that consider themselves popular will be shocked to learn that they have few lawmakers after the August 8 General Election.
"Let the other parties not boast because of changed laws that give them more funds," he said.
DP leader Joseph Munyao said the party would field candidates for all positions, except the presidency, in all counties.