Zimbabwe's First Lady Grace Mugabe Thursday openly challenged her 93-year old husband to name his successor.

Zimbabwean President Robert Mugabe last month was also challenged by War Veterans Minister Tshinga Dube to name his successor in order to "boost investor confidence".

But now, in a surprising turn of events, his wife, Grace, has brought back the subject, openly doing so while she addressed the meeting of the ruling party's women wing at the party headquarters in the capital Harare.

"There is nothing wrong with President Mugabe naming his successor; the move will enable all members of the party to rally behind one candidate," the Zimbabwean First Lady said in her address to the Women's League.

Two factions are battling to succeed Mugabe in his Zanu-PF party, one reportedly led by one of Mugabe's deputies, Emerson Mnangagwa. The other one is also allegedly led by the country's first lady.

For Mugabe, the first lady said, naming of his successor would not be a new phenomenon as "this has been a trend in other countries".

Meanwhile, Grace called for the amendment of Article 7.1.b of the Zanu-PF constitution to restore the provision that stipulates that one of the two vice presidents and second secretary of the party shall be a woman.

The Zanu-PF party has ruled the southern African country since its independence in 1980. Zimbabwe's nonagenarian President Robert Mugabe will stand for re-election in 2018.

The country is expected to hold elections anytime between March and June next year.