HARARE (Reuters) -Lawmakers from Zimbabwe's main opposition party MDC will hold a meeting on Tuesday to decide whether to join their ruling party rivals to impeach 93-year-old President Robert Mugabe, the minority chief whip said.
Although Mugabe's ZANU-PF has the required two-thirds membership to remove Mugabe, participation by the opposition could give a boost to a process that was started by the military's intervention last week.
Impeachment could see Mugabe kicked out by a vote in parliament in under a day and would represent an ignominious end to the career of the "Grand Old Man" of African politics, who was once lauded across the continent as an anti-colonial hero.
On paper, the process is relatively long-winded, involving a joint sitting of the Senate and National Assembly, then a nine-member committee of senators, then another joint sitting to confirm his dismissal with a two-thirds majority.
However, constitutional experts said ZANU-PF had the numbers and could push it through in as little as 24 hours.
"They can fast-track it. It can be done in a matter of a day," said John Makamure, executive director of the Southern African Parliamentary Support Trust, an NGO that works with the parliament in Harare.
Mugabe's demise, now almost inevitable, is likely to send shockwaves across Africa, where a number of entrenched strongmen from Uganda's Yoweri Museveni to Democratic Republic of Congo's Joseph Kabila are facing mounting pressure to step aside.
Mugabe was once admired, even in the West, as the "Thinking Man's Guerrilla", a world away from his image in his latter years as the stereotypical African dictator proudly declaring he held a "degree in violence".
As the economy crumbled and opposition to his rule grew in the late 1990s, Mugabe tightened his grip around the southern African country, seizing white-owned farms, unleashing security forces to crush dissent and speaking of ruling until he was 100.
ZANU-PF's action follows a weekend of high drama in Harare, culminating in reports that Mugabe had agreed on Sunday to stand down -- only for him to dash the hopes of millions of his countrymen in a bizarre and rambling national address.
Flanked by the generals who sent in tanks and troops last week to seize the state broadcaster, Mugabe spoke of the need for national unity and farming reform, but made no mention of his fate, leaving the nation of 16 million people dumbstruck.
"I am baffled. It's not just me, it's the whole nation," shocked opposition leader Morgan Tsvangirai told Reuters. "He's playing a game."
Two senior government sources told Reuters Mugabe had agreed on Sunday to step aside and CNN said on Monday his resignation letter had been drawn up, with terms that included immunity for him and his hot-headed and unpopular 52-year-old wife Grace.
It was her tilt at power via the purging of former vice-president Emmerson Mnangagwa this month that forced the army to send in the troops.
Two other political sources told Reuters on Monday Mugabe had indeed agreed to resign but ZANU-PF did not want him to quit in front of the military, an act that would have made its mid-week intervention look like a coup.
"It would have looked extremely bad if he had resigned in front of those generals. It would have created a huge amount of mess," one senior source within ZANU-PF said.
Another political source said the speech was meant to "sanitise" the military's action, which has paved the way for Mnangagwa, a former security chief known as The Crocodile, to take over.
Moments after his address, war veterans' leader Chris Mutsvangwa, who has spearheaded an 18 month campaign to unseat Zimbabwe's only leader, called for protests suggesting a potential popular uprising if Mugabe refused to go.
On Saturday, hundreds of thousands took to the streets of Harare to celebrate Mugabe's expected downfall and hail a new era for their country, whose economy has imploded under the weight of economic mismanagement, including 500 billion percent hyperinflation in 2008.
An estimated 3 million Zimbabweans emigrated to neighboring South Africa in search of a better life.
The huge crowds in Harare have given a quasi-democratic veneer to the army's intervention, backing its assertion that it was merely effecting a constitutional transfer of power, rather than an old-style coup, which would risk a diplomatic backlash.
Behind the euphoria, some Zimbabweans have misgiving, not least because of the prominent role played by the military in removing Mugabe.
"The real danger of the current situation is that, having got their new preferred candidate into State House, the military will want to keep him or her there, no matter what the electorate wills," former education minister David Coltart said.
Other's worry about Mnangagwa's past, particularly as state security chief in the early 1980s, when an estimated 20,000 people were killed in the so-called Gukurahundi crackdown by the North Korean-trained Fifth Brigade in Matabeleland.
He has denied any wrong-doing but critics say Zimbabwe risks swapping one army-backed autocrat for another.
"The deep state that engineered this change of leadership will remain, thwarting any real democratic reform," said Miles Tendi, a Zimbabwean academic at Oxford University.
(By Joe Brock and MacDonald Dzirutwe; Additional reporting by Harare and Johannesburg bureaux; Writing by Ed Cropley; Editing by Angus MacSwan)