The motion is now due to be presented to parliament on Tuesday.
Senior party member Paul Mangwana said the process could take as little as two days to complete, and President Mugabe could be removed by Wednesday.
A deadline set by Zanu-PF for his resignation passed on Monday.
Separately, military leaders said they had planned a "roadmap" for Mr Mugabe's future, and that the ousted former vice-president, Emmerson Mnangagwa, would return to the country soon.