Chinhoyi - Zimbabwe's First Lady Grace Mugabe has warned her husband's deputies that they risk losing their jobs if they do not perform to the expectations of the 93-year-old leader.Addressing thousands of ruling Zanu-PF supporters at a rally held on Saturday at the Chinhoyi University of Technology, the First Lady said vice presidents served at President Robert Mugabe's will.This came at a time when one of Mugabe's deputies, Emmerson Mnangagwa, was reportedly leading a faction within the ruling Zanu-PF party that was angling to take over power when the nonagenarian eventually left office."At one point I received calls from people within the party who wanted us to go into the streets and demonstrate against Mnangagwa because they were not happy with him," said Grace.'I am not going nowhere' "I told them that vice presidents are appointed by the president and they serve at his mercy. So they must act in a manner that pleases the president," she added.The First Lady last week called on Mugabe to name his successor. Grace, who was reportedly leading a faction that wanted to torpedo Mnangagwa's presidential ambitions, called on her husband to appoint a female vice president.President Mugabe, however, said he was not ready to leave office any time soon, arguing that any new presidential candidate that would face off with former premier Morgan Tsvangirai of the main opposition Movement for Democratic Change party would be defeated."Some are saying I'm going, I am not going anywhere. Some are saying I am dying, I am not dying," said the veteran leader.Mugabe, who has failed to groom a successor in 37 years in power, said his party was sharply divided and called for unity among Zanu-PF members as Zimbabweans prepared for general elections due next year.