Wiper chairman Kivutha Kibwana has hit out at party leader Kalonzo Musyoka again, in the clearest pointer yet to the widening rift between the two.
Prof Kibwana said the agreement Mr Musyoka struck with President Uhuru Kenyatta would not benefit the Ukambani region "because it was badly negotiated".
The Makueni governor added that the deal sounds the death knell for development in the region.
"The President has focused the country on the Big Four agenda. To what extent have regional political leaders helped the southeastern people access national development?" Prof Kibwana asked in a statement seen by the Nation Monday.
"Even when we got a chance to visit State House recently, we did not prepare adequately to engage the President in a development dialogue the way the National Super Alliance leader is doing."
The statement just came days after Mr Musyoka openly spoke about his bargain with Mr Kenyatta for the first time.
During a Kamba cultural festival at Nguni Primary School in Kitui County on Friday, Mr Musyoka said he agreed to work with the President "to boost his fight against corruption, while ensuring cohesion and peace in the country".
This explanation was preceded by virulent attacks by Wiper MPs who accompanied the party leader against those questioning the agreement.
The governor has joined a group of Ukambani elites questioning Mr Musyoka's commitment to the region's development.
"Stephen Kalonzo Musyoka has been in office since 1985, (Kitui Governor) Charity Ngilu since 1992, Kivutha Kibwana since 2002 and (Machakos Governor) Alfred Mutua since 2013. Maybe it is time the community summons us -- including former Machakos Senator Johnson Muthama -- to account for our work and vision," Governor Kibwana's statement went on.
One of the challenges facing Mr Musyoka is Prof Kibwana's call for him to take advantage of his ties with Mr Kenyatta to reach out to Dr Mutua and politicians who defected to Jubilee but lost in the August 2017 election.
The governor says doing so would forge a solid voting bloc worthy of an invitation to the negotiating table ahead of the 2022 General Election.
Prof Kibwana surprised Mr Musyoka's supporters last year during a meeting in Tala when he said other leaders from the region with presidential ambitions should not be admonished.
Kitui Senator Enock Wambua, MPs Gideon Mulyungi (Mwingi Central), Daniel Maanzo (Makueni), Makueni Woman Rep Rose Museo and a several MCAs have accused those faulting the Wiper leader's deal with Jubilee Party of undermining Mr Musyoka.