This Wednesday Morgan Tsvangirai will get his third crack at dethroning veteran Zimbabwean leader Robert Mugabe.

It may be his last.

In 14 years at the helm of the Movement for Democratic Change, the 61-year-old ex-trade unionist, has made his party the only credible alternative to Mugabe's ZANU-PF.

In consecutive elections in 2002, 2005 and 2008 Tsvangirai has run Mugabe close.

Last time out he won 47.9 percent of the vote to Mugabe's 43.2 percent.

In a fair race, he may well have won outright. But an orgy of violence against allies forced him out of the hunt before the final round of voting.

For his troubles Tsvangirai has been arrested repeatedly, been charged with treason and faced four suspected assassination attempts.

In 1997 assailants tried to throw him out of his office window.

His bodyguard has been killed and his wife died in a suspicious car crash that also hospitalised him.

He retains a strong following among urbanites and Zimbabweans in rural of the western part of the country.

But even among supporters, there is a lingering sense that Tsvangirai has repeatedly been outmanoeuvered by Mugabe, even when the international community forced Mugabe to accept him as prime minister.

After more than four years of a forced unity government, most meaningful levers of power -- from the security services to the judiciary -- remain under Mugabe's control.

Tsvangirai has been criticised for offering Mugabe legitimacy by participating in polls that have repeatedly been rigged -- and for failing to mobilise mass protests that could shift the terrain in his favour.

And on his watch, the MDC has split into two rival factions, draining energy and valuable votes.

He has managed to forge an alliance with Simba Makoni, a former finance minister and senior official of Mugabe's party, who came third in the first round of the 2008 elections.

"This will be a do-or-die election for him," said Eldred Masunungure, a political scientist at the University of Zimbabwe.

"After being at the helm of the party since September 1999, if he loses, then surely he must consider dropping the hat for someone else."

While he is widely seen as a champion of democracy, recent scandals surrounding his love life, including a public divorce, have put a dent in his popularity.

He "gets distracted by a whole lot of things, including personal issues," said South African analyst Moeletsi Mbeki, who has known Tsvangirai since the 1980s.

The does little to help strengthen his fight especially facing a "very powerful adversary" like Mugabe.

"Morgan has been learning on the job while fighting against... Mugabe (who) is the one of the cleverest politicians in Africa."

Mbeki thinks that "in fact Morgan has done reasonably well given the lack of experience he started off with."

The teetotal, non-smoking Tsvangirai rose to political prominence via the trade union movement.

After working for 10 years at Bindura Nickel Mine he became leader of the country's largest labour federation, spearheading national strikes in the 1990 against Mugabe's economic policies.

He was born in 1952, the son of a bricklayer in the southern town of Gutu, as the oldest of nine children.

He grew up in the eastern district of Buhera but family poverty forced him to quit school early and earn a living to enable his younger siblings to get an education.

Unlike most of Zimbabwe's politicians of his age and older, Tsvangirai did not take part in the Chimurenga liberation war against white colonial rule.

He was 28 when Zimbabwe won independence from Britain in 1980.

Under Mugabe's rule, he was detained twice for his political activism and was twice cleared of treason charges.

In March 2007, he was among dozens of opposition activists assaulted by police as they tried to stage an anti-government rally, and suffered head injuries.

Just three weeks after taking office as the premier, his first wife Susan died in a car crash that also left him hospitalised.

There are increasing signs his long struggle has taken its toll.

"I don't have the 'I-will-not-go' attitude. When my days are done, I will go and leave these young ones (to it)," Tsvangirai told thousands of supporters on Sunday.