Zimbabweans began voting on Saturday in the most crucial election since independence from Britain in 1980, with veteran President Robert Mugabe facing the biggest challenge of his 28-year-rule.

Voting began at 0706 a.m. (1:06 a.m. EDT) and was scheduled to end 12 hours later.

With the once-prosperous nation's economy in ruins, former guerrilla leader Mugabe must defeat a formidable two-pronged attack from veteran opposition leader Morgan Tsvangirai and ruling party defector Simba Makoni.

His two rivals believe they can finally end Mugabe's iron rule because of an economic meltdown that has reduced most of the population to misery, including those in his traditional rural strongholds.

Zimbabwe, once a regional breadbasket, now suffers the world's worst inflation at 100,000 percent, a rampant HIV/AIDS epidemic that has contributed to a radical reduction in life expectancy, a virtually worthless currency and chronic shortages of food and fuel.

But few analysts are prepared to count Mugabe out.

They say he has maintained a tight grip on power through a combination of ruthless security crackdowns, intimidation of ruling party rivals and an elaborate patronage system. A split opposition may also favor Mugabe.

Supporters both inside the country and elsewhere in Africa still revere him as the last of the liberation heroes.

Tsvangirai, a former trade unionist who has long posed the greatest threat to Mugabe, and former finance minister Makoni say the economic catastrophe will not end unless the veteran leader is replaced.

Security forces

But Zimbabwe's powerful security forces have thrown their backing behind Mugabe, stoking accusations that he will use his incumbent power to rig victory.

The state-owned Herald newspaper reported on Friday that an opinion poll showed Mugabe would win up to 57 percent of the vote, which analysts saw as a way of preparing the population for his victory. The poll was conducted by a university lecturer seen as sympathetic to the government.

Tsvangirai and Makoni said on Thursday Mugabe planned to declare victory with almost 60 percent of the vote after a fraudulent count.

The Zimbabwe Electoral Commission on Friday rejected opposition accusations that the voters roll was padded with many non-existent "ghost voters" to ensure ZANU-PF victory.

"I maintain that the voters roll is very credible (although) it is not perfect," commission chairman George Chiweshe told reporters, although he conceded some dead people could be on the rolls.

"Deaths occur every day, we will never be able to catch up with them," he said.

Mugabe blames the economic collapse on sanctions by former colonial power Britain and other Western nations.

"This is a vote against the British. The fight is not against the MDC ... the MDC is just a puppet, a mouthpiece of the British," he said in one of his last rallies on Friday.

If no candidate wins more than 51 percent of the vote on Saturday, the election will go into a second round, when the two opposition parties would likely unite. Critics say Mugabe will do his utmost, including rigging, to avoid this happening.

PHOTO CAPTION

Zimbabwe's President Robert Mugabe greets supporters after arriving for his final election rally at Highfields in Harare March 28, 2008.

Reuters