Grace was believed to be the leader of the Zanu-PF faction known as the Generation 40 (G40) which had pushed Mnangagwa out of the party before her husband was ousted.
According to the privately-owned Standard newspaper, Mnangagwa told his supporters in Marondera over the weekend that the Zanu-PF party would no longer tolerate insults.
“On July 30, Zanu-PF is going to demonstrate peacefully that it is a great party,” Mnangagwa was quoted as saying.
“We are a great party and gone are the days of insults. The party had people full of insults, I am talking of G40 here. The G40 is still there, down with them.”
In May, NewsDay reported that under Mugabe’s rule, Grace used her husband’s rallies to throw insults at her perceived opponents.
She was instrumental in the sacking of Mnangagwa as vice president just days before the military took over and forced Mugabe’s resignation.