FILE PHOTO: Zimbabwe's President Robert Mugabe looks on as his deputy Emmerson Mnangagwa reads a card during Mugabe's 93rd birthday celebrations in Harare, Zimbabwe, February 21, 2017. REUTERS/Philimon Bulawayo/File Photo

HARARE (Reuters) - Zimbabwe’s former vice president Emmerson Mnangagwa, who was sacked by President Robert Mugabe this week, has been expelled from the ruling Zanu-PF, a party spokesman said on Wednesday.

Mnangagwa, a liberation war veteran and a long-time ally of Mugabe, was until this week seen as a favorite to succeed the 93-year-old leader.

But Mnangagwa’s relationship with Mugabe’s wife, Grace, has become increasingly strained as their two factions within Zanu-PF fight for dominance. Mnangagwa’s removal on Monday came two days after Grace publicly called him a “coup plotter”.