A President Emmerson Mnangagwa aide says ruling party Zanu-PF should have "clipped" former president Robert Mugabe's rule much earlier to avoid a nasty succession battle that has rocked the party in recent years, according to state-owned newspapers. Zanu-PF executive member Perrance Shiri believes that allowing the former president to stay so long in office created a vacuum in the party's internal processes as Mugabe's advanced age clearly became a problem, the state-owned Herald newspaper reported. The lands, agriculture and rural settlement minister said a cabal linked to Mugabe's wife, Grace, was then able to launch attacks against senior party leaders in a bid to drive a wedge between them and Mugabe who was "vulnerable" due to old age. Shiri said the ruling party should take a leaf from the book of other liberation movements in the region on how to handle succession to avoid a similar occurrence, reported another state owned paper Chronicle. An AFP report last year quoted an analyst as saying Mugabe's downfall was caused by the ambitions of his combative wife, whose emergence as his likely successor proved a step too far for Zimbabwe's military. Grace – 41 years younger than her husband – was once dismissed as a lightweight shopping addict.But she became increasingly active in public life in recent years, and became the frontrunner to take the top job when Mugabe sacked her then arch-rival, Mnangagwa.The military – determined to stop Grace, 53, being named as the new vice president – moved to take control of the country and signal the imminent end of Mugabe's rule.Mnangagwa was then installed as the country's third president since its independence in 1980. * Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTERFOLLOW News24 Africa on Twitter and Facebook.