Borabu MP Ben Momanyi will no longer transact business on behalf of the County Government of Nairobi, Mike Sonko has said.
The latest directive is a culmination of the vicious tag of wars between the duo that has seen them even spat on each other publicly.
In a statement from the office of the governor, all firms that have been representing City Hall in various cases will no longer be tolerated.
"Our lawyers have been colluding with cartels and it is time that I acted. From today, the firms acting on our behalf remain dismissed," he said in reference to Momanyi's Orori firm.
He added: "They have been swindling millions without our consent making us undergo severe losses."
On Tuesday, Sonko had asked the DCI to investigate Momanyi, who he accuses of consenting payment of Sh6.2 million to General Suppliers Limited irregularly.
Also, the governor had moved to court to demand refund of Sh58 million paid to Momanyi's firm as part of Sh60 million which the court had rendered 'defective and unnecessary'.
In his defense, Momanyi, who is currently in US for PSC seminar, has accused the governor of making judgments out of emotions.