Cape Town - Democratic Alliance leader Mmusi Maimane has urged the United Democratic Movement to reconsider its threat to leave the Nelson Mandela Bay metro coalition.Maimane was responding to a letter from UDM leader Bantu Holomisa on Thursday, who had indicated that the party would be leaving the city's coalition unless ousted deputy mayor Mongameli Bobani was reinstated by Monday.Bobani was voted out following a controversial vote of no confidence in the city council on Thursday, following DA allegations of corruption.In his own letter on Thursday, Maimane said Holomisa's ultimatum was holding the co-government agreement "to ransom"."It requests of us to maintain the status quo, despite the evidence of corruption, and despite Cllr Bobani flagrantly voting against the coalition," Maimane said."This is unworkable and illegal in our view. It would make us no different to the ANC government we have replaced, and it is a betrayal of the faith voters placed in us to deliver a totally different style and ethos of government."READ: UDM to pull out of coalition unless Bobani is reinstated'Right thing to do'Maimane maintained that the passing of the motion of no confidence in Bobani was no cause for celebration for him, nor for their coalition partners.The other partners include the African Christian Democratic Party, the Congress of the People and the Freedom Front Plus."The firing of Cllr Bobani through a motion of no confidence is the painful end to a matter that has drawn out for nearly 12 months," Maimane said."However, we have no doubt that it was the right thing to do for the residents of the Nelson Mandela Bay, and particularly those residents who voted for an entirely different government than the corrupt and untrustworthy government that came before."Voters had put the coalition in place in Nelson Mandela Bay for that reason, to root out corrupt practices of the former African National Congress government, Maimane said.READ: DA 'bullying' UDM in Nelson Mandela Bay, says EFFUDM entitled to another councillorBobani had not upheld the spirit of the co-governance agreement, he said. He had openly voted with the ANC in council, contradicted Mayor Athol Trollip at a separate event, and accused the DA government of "spurious charges", including illegally evicting residents."Moreover, two separate forensic reports conducted by independent third party auditing firms have found serious prima facie evidence of maladministration, fraud, and tender irregularities involving departments directly under the operational and political authority of Cllr Bobani."Maimane insisted the removal of Bobani was not the removal of the UDM."The UDM is still fully entitled and encouraged to take up a position in the mayoral committee in Nelson Mandela Metro with another councillor of their choice."It must be noted at this point that the coalition partners have jointly shown extreme patience and tolerance in handling this matter."Maimane said the coalition had taken numerous steps to address the issue, including setting up a multi-party intervention team.'UDM protecting Bobani like ANC protects Zuma'Despite this, the UDM had failed to take action against Bobani, despite having had ample opportunity and evidence to do so."The UDM has vocally campaigned for the removal of President Jacob Zuma for similarly destructive and unethical (and allegedly illegal) behaviour."It would seem to any observer that Cllr Bobani's position in the UDM is similar to that of Mr Zuma in the ANC: Everyone knows he is fundamentally at odds with the law and the values of the Constitution, but no one in his own party is prepared to remove him."He also criticised Holomisa for using the impasse to "race bait", and using language in public referencing apartheid-style racial segregation and the like."The charge that we are 'dictating' to the UDM is also without substance. Were this true, a motion of no confidence would not have been necessary. We have merely dealt with the violations of the co-governance agreement and the evidence of corruption before us."'UDM must explain collapse to voters'At the end of the day, the situation with Bobani has become unworkable, hence the ACDP and Cope also voting for the motion, Maimane argued.He proposed that the UDM nominate another councillor in Bobani's place, as the DA could not tolerate "this kind of unethical conduct."We will gladly support any other UDM nominee," he said, urging Holomisa to continue the stability of the coalition's working relationship."If you decide to go through with your ultimatum and collapse the government, then it will fall to you to explain to the voters of Nelson Mandela Bay and the people of South Africa, who have taken such strength and hope from our coalition, why you decided to return the ANC to government and protect the conduct of one man over the interests of the country."He was hopeful that the parties could heal the mistrust, and proceed forward.