Zimbabwe's President Robert Mugabe speaks at a rally in Harare as he sought to assert his grip on power following recent protests and infighting within his ruling Zanu-PF party Wilfred Kajese/ AFP

The race to replace ageing Zimbabwe's President Robert Mugabe has just turned nasty after an opposition member of parliament claimed the nation was asking when Mugabe is going to die.

The battle to succeed Zimbabwe's 92-year-old president may be decades in the making, but its outcome is far from settled. The situation is further complicated by the incumbent's refusal to publicly identify a favoured replacement, instead opting to hang on to power indefinitely, and keep his potential successors guessing. With 2018 the general election rearing its head, Vice President Emmerson Mnangagwa emerged as a frontrunner in the, as yet, unofficial race to replace Mugabe within the ruling Zanu-PF party.

It has now emerged that an outspoken legislator from the opposition MDC party, MP Priscilla Misihairabwi-Mushonga, shocked Parliament on 18 October when she spoke about Mugabe's imminent retirement and claimed Zimbabweans were asking when the president was going to die.

Referring to the ongoing Zanu-PF succession battles between Mnangagwa and the First Lady Grace Mugabe, Misihairambwi-Mushonga said the country was "at a standstill" as people were expecting announcements about Mugabe's retirement and succession plan.

"I think we need to get the president to address all these issues to deal with the issue around succession. Succession has become a cancer in this country," the MDC MP told Parliament, according to local reports.

"No one works because everybody is waiting to see when Robert Mugabe is going to die and when he is going to get sick. (...) Yes, I am not saying I want him to die. I am saying the very fact that as a nation, we are now bound to waking up in the morning and people wanting somebody to die, is an indication that we have a problem."

A man hold placards during a protest against President Robert Mugabe government's handling of the economy in Harare Philimon Bulawayo/ Reuters

Claiming the nation is "sick and tired (...) of being held to ransom over Zanu-PF politics of not being able to choose a person that they want", the vocal legislator added: "We do not care whether President Mugabe stays or not. We have an election to go and get rid of him. These are the people that we want to get rid of him in his party."

Misihairambwi-Mushonga urged Mugabe to address the problem.

First Lady or Vice President: Who will succeed Mugabe?

Tensions have been rising as a progressively tense fight over who will succeed him intensified within Zanu-PF ranks between his 50-year-old wife and Mnangagwa, who are at the centre of ever-deepening faction fights for the top position.

Mnangagwa, a liberation war hero known as the "Crocodile", has enjoyed strong backing among the security forces because of his career in the defense ministry and is supported by a faction called Team Lacoste.

While the G40 backs the president's wife, Mnangagwa's allies within Team Lacoste have made no bones about the fact that the president should retire to make way for his vice president - something that has not escaped the notice of the first lady who in February suggested that she is out to get Mnangagwa.

Referring to the inside infighting, which prompted the ouster of the leader's former vice president, and long-time allyJoice Mujuru – who launched her new party, Zimbabwe People First (ZPF) on 1 March to challenge the president's 35-year rule – Mugabe earlier this year said Zanu PF's discussion over succession was alien to Zimbabwe and that the core structures of the party were undivided.

Mugabe also dismissed speculation that his wife could take over from him, and said he will neither choose a successor nor retire as that would be against the party conventions.

Zimbabwe's First Lady Grace Mugabe
Zimbabwean President's wife, Grace Mugabe raises her fist as she addresses at a rally in Harare on July 28, 2013. ALEXANDER JOE/AFP/Getty Images