Former TNA secretary-general Onyango Oloo is expected to announce his defection from President Uhuru Kenyatta’s camp and join the Orange Democratic Movement (ODM).
Mr Oloo said he will officially announce his move to the Raila Odinga-led party on Wednesday.
He is expected to lead a host of other Jubilee party members who will be crossing over to the Opposition.
“I will be making the official announcement on Wednesday at 8:30am at the Public Service Club in Kisumu where I will give details of my move,” he said by phone.
Mr Oloo will thereafter join Mr Odinga in his tours to mobilize Kenyans to register as voters ahead of the August 8 elections.
He was left out in the line-up of the new Jubilee party launched by President Uhuru Kenyatta and his deputy William Ruto in September last year.
His contract as the chairman of the Lake Basin Development Authority was also not renewed last year.
He was replaced by former Rarieda MP Raphael Tuju, who also appeared to have edged him out of the ruling coalition’s top leadership position.
Mr Tuju is the head of President Kenyatta’s campaign secretariat.
ODM secretary-general Agnes Zani, director of elections Junet Mohammed and director of political affairs Opiyo Wandayi welcomed Mr Oloo’s move, saying it was a sign the Jubilee administration had started crumbling before the polls.
However, National Assembly Majority Leader Aden Duale has said Mr Oloo had joined many other politicians who have defected from their parties to join others, adding that there was nothing new for the former TNA strongman joining a party from his region.
TNA-nominated Senator Joy Gwendo said she was in the Jubilee party to stay.
URP activist George Ayugi said Mr Oloo’s move was “good riddance”.
“It is his democratic right but we must tell our people in Nyanza that Jubilee will still recapture power and it is high time they joined the government,” Mr Ayugi said.