In his plea for Maimane's intervention, Msimanga detailed the problems that Mosola has caused the DA-led city. He claims even service delivery has deteriorated as a result of their bitter fight.
He has asked Maimane to speak to the EFF to persuade it to support a move to suspend or remove Mosola.
Msimanga accused Mosola of threatening officials almost on a weekly basis because they refuse to do wrong.
"Blatantly unlawful instructions such as issuing of a press statement by the city in which a political party [DA] is attacked by the city manager, are given . yet the city manager faces no consequences for his actions.
"The incentive is for officials to only follow the instructions of the city manager and ignore most of MMCs," the letter read.
"We have crucial tenders that never get to be awarded, recommendations and appointment letters sit on the city manager's desk for a long time, waiting for his signaturewhile services suffers."
Msimanga accused Mosola of allowing contracts to lapse, which compels the city to move into extensions.