Zimbabwe's military seized power early on Wednesday and since then Mugabe has refused to resign.
Ruling ZANU-PF has drafted an impeachment motion that said Mugabe was a "source of instability", had shown disrespect for the rule of law, and was to blame for an unprecedented economic tailspin over the past 15 years.
Mugabe is also accused of allowing his wife, Grace Mugabe, to "usurp constitutional power".
The ZANU-PF party reportedly discussed the 93-year-old leader's impeachment on Monday, after a noon (9:00pm AEDT) deadline expired for him to resign after nearly four decades in power.
On paper, the impeachment is relatively long-winded, involving a joint sitting of the Senate and National Assembly, then a nine-member committee of senators, then another joint sitting to confirm his dismissal with a two-thirds majority.
The ruling party has chosen Emmerson Mnangagwa to replace Mugabe.
Mnangagwa, a veteran of the liberation war and for decades Mugabe's right-hand man, fled into exile earlier this month after being ousted from his position in government and Zanu-PF by a faction allied to the president's wife. (ANI)