Johannesburg - United Democratic Movement leader Bantu Holomisa has issued a fresh demand for an apology from Democratic Alliance leader Mmusi Maimane as relations between the two coalition partners deteriorate.This time Holomisa wants Maimane to apologise for "besmirching" his party over a "fickle" draft report by audit company PricewaterhouseCoopers (PwC).Relations between the two parties are at an all-time low after the DA pushed through a motion of no confidence in the UDM's Nelson Mandela Bay deputy mayor Mongameli Bobani.READ: Bobani files court papers to be reinstated as deputy mayorThe DA found a new coalition partner in the Patriotic alliance that helped win the motion, despite unhappiness from other parties, including the Economic Freedom Fighters.The UDM has taken the DA to court, accusing the party of undermining it as a coalition partner and violating the agreement that saw them unseat the African National Congress following the August 2016 local government elections.'Untenable' behaviourIn a letter dated September 13, from Holomisa to Maimane, the UDM leader says Bobani was removed under "false pretences".He said PwC was yet to form an opinion on the investigation into allegations that senior staff had complained that Bobani had put pressure on them to hire 217 more temporary workers than budgeted for at three depots in the city."The fecklessness of the 'draft report' forced you to keep it secret, but it did not preclude you from (ab)using it. You and your colleagues have publicly criticised me (personally), saying that we condone corruption," Holomisa wrote.READ: Bobani swore at me in parting shot - TrollipBobani has repeatedly denied the claims. Holomisa said the report was yet to be presented to the council, but had been shown to Maimane."The UDM would like to see you publicly and unreservedly withdraw your unsubstantiated accusations and apologise to me, to Cllr Bobani and to the UDM. Prove to the nation that you are better than the manipulative, destructive liars within the ANC who you purport to oppose," Holomisa said.Nelson Mandela Bay Metro Mayor Athol Trollip has also argued that Bobani was removed on August 24 for voting against decisions by the coalition, along with EFF and ANC members.He accused him of causing instability as a councillor, and said that his behaviour was "untenable".