Cape Town - The calls by Cosatu-affiliated unions for President Jacob Zuma to resign are "strange", as the African National Congress has never interfered with the leadership of these unions, ANC national spokesperson Zizi Kodwa said on Friday.Kodwa said the party had noted the public pronouncements by some unions recently, but that the ANC's national executive committee (NEC) would ultimately decide the fate of its next president."We respect Cosatu as a strategic alliance partner. We also respect their independent processes on how it elects its leaders," he told News24."We have never participated as the ANC in the leadership of Cosatu, but have always supported its leader elected by its affiliates."We find it strange that Cosatu-affiliates have continued even to call for the resignation of the leader of the ANC."Kodwa was referring to recent calls by the National Health and Allied Workers Union (Nehawu) and the Communication Workers Union (CWU) for Zuma to resign following widespread criticism of his leadership of state institutions.Zuma’s leadershipREAD: Time for Zuma to go - CWUThe CWU said on Thursday that Zuma had played his role and it was now time for him to step down. It said the country was lurching from "one crisis to another", and that he should leave with immediate effect.Nehawu said two weeks ago that it could no longer be denied that Zuma's leadership had become "untenable", and publicly backed Deputy President Cyril Ramaphosa to become the next party leader.Kodwa said the leadership of the ANC would only be changed at the party's elective conference in December 2017, and that the current leadership would now hold discussions with its provincial branches ahead of that."We would invite those in Cosatu, who want to participate in the leadership of the ANC, to be part of the ANC branch meetings."It was their right to attend and make their voices heard, but must do so as ANC members, he said.He called on all alliance members to build, defend and protect the unity of the alliance.