"Cabinet meeting called this morning by President Mugabe failed to take off after Ministers snubbed the sitting," the state-run Herald news site reported.
Lawmakers of Mugabe's once-loyal ZANU-PF party were to meet parliamentarians from other parties at 1215 GMT to trigger proceedings that could see the president stripped of office.
The cabinet snub piled further pressure on the embattled president after Emmerson Mnangagwa, the vice president whose removal by Mugabe sparked the military intervention last week, earlier said he would consider returning to Zimbabwe if his safety was guaranteed.
The dismissal put Mugabe's wife Grace in prime position to succeed her 93-year-old husband, prompting the military to step in to block her path to the presidency.