Harare - Zimbabwe President Robert Mugabe's 37-year rule appeared to have come to an end on Sunday after a source confirmed he had agreed to resign and was preparing to address the nation. Mugabe's grip on power was broken last week when the military took over, angered at his wife Grace's emergence as the leading candidate to succeed the 93-year-old president. "Yes he has agreed to resign," a source close to the presidency told AFP after Mugabe's expected television address to the nation was delayed. At a ruling ZANU-PF party meeting earlier in the day, delegates cheered wildly as a party official announced that Mugabe had been ousted as party chief.He was replaced by former vice president Emmerson Mnangagwa, who had been Grace Mugabe's chief rival.Follow our life update here In a stunning reversal of allegiances, the party added that it would impeach Mugabe if he did not resign by Monday, Mnangagwa would be its candidate in 2018 elections, and that Grace was expelled from the ZANU-PF ranks. Robert Mugabe - the world's oldest head of state - remained national president until his official announcement but was overwhelmed by opposition from the generals, much of the Zimbabwean public and from his own party. "(Mugabe's) wife and close associates have taken advantage of his frail condition to usurp power and loot state resources," party official Obert Mpofu told the ZANU-PF meeting. Army chief Constantino Chiwenga held further talks with Mugabe on Sunday at State House, the president's official residence. Official photographs of the meeting showed one officer saluting the president, who stood behind his desk, and several senior officers sitting in a formal room with white sofas and a bright red carpet. No details of the meeting were released. Historic week The two sides first met on Thursday in an attempt to present a dignified image of the tense process of negotiating Mugabe's departure. Veterans of the independence war - who were also formerly key Mugabe allies - added their voice in support of him resigning, demanding that he leave office immediately. Zimbabweans have experienced a historic week in which the military seized power and put Mugabe under house arrest in response to his sacking of vice president Mnangagwa, who has close military ties. On Saturday, in scenes of public euphoria not seen since Zimbabwe's independence in 1980, huge crowds marched and sang their way through Harare and other cities in peaceful celebrations marking the apparent end of his long, authoritarian rule. The demonstrations drew citizens of all ages, jubilant that Mugabe appeared to be on his way out. In central Harare, a group of young men tore down a green metal street sign bearing Robert Mugabe's name and smashed it repeatedly on the road. Such open dissent would have been routinely crushed by security forces before this week's fast-evolving events. Peace, jobs, a normal life"What you saw yesterday, it shows that the people have spoken," Mordecai Makore, 71, a retired teacher told AFP after attending a Sunday morning service at the Catholic cathedral in central Harare. "All we want is peace, a good life with a working economy that creates jobs for our people. We will continue praying for that. I want my children and grandchildren to live a normal good life." The majority of Zimbabweans have only known life under Mugabe's rule, which has been defined by violent suppression, economic collapse and international isolation. Sources suggest Mugabe has been battling to delay his exit and to secure a deal guaranteeing future protection for him and his family. The factional succession race that triggered Zimbabwe's sudden crisis was between party hardliner Mnangagwa - known as the Crocodile - and a group called "Generation 40", or "G40", because its members are generally younger, which campaigned for Grace's cause. "She is very acceptable. Very much accepted by the people," Mugabe said of Grace in a faltering interview to mark his 93rd birthday last February. The president, who is feted in parts of Africa as the continent's last surviving independence leader, is in fragile health. But he previously said he would stand in elections next year that would see him remain in power until he was nearly 100 years old. He became prime minister on Zimbabwe's independence from Britain in 1980 and then president in 1987. Zimbabwe's economic output has halved since 2000 when many white-owned farms were seized, leaving the key agricultural sector in ruins.