Zimbabwe President Robert Mugabe's party claimed Friday that he is on course for a landslide win, in an election branded a sham by his rivals, but which the African Union said was fair and credible.
Partial results of Wednesday's poll have given the 89-year-old a commanding lead, with his ZANU-PF party garnering 87 seats out of 120 declared.
"Our opponents don't know what hit them," party spokesman Rugare Gumbo said. "It's the prediction that the president might likely get 70 to 75 %."
ZANU-PF also predicted it would win a two-thirds majority in parliament, enough to amend the new constitution that introduced term limits and curbed presidential powers.
Mugabe's bitter rival Morgan Tsvangirai has rejected the vote as a "huge farce" and "null and void".
"It's a sham election that does not reflect the will of the people," he said, pointing to a litany of alleged irregularities with the voters' roll.
The independent Zimbabwe Election Support Network reported up to one million voters were prevented from voting in Tsvangirai strongholds.
But Mugabe won an endorsement from the African Union on Friday, with former Nigerian president and military leader Olusegun Obasanjo saying the vote was basically free and fair.
"There are incidences that could have been avoided, but all in all we do not believe that these incidents will amount to the results not reflecting the will of the people," he said.
Much now rides on the verdict of observers from the 15-member southern African SADC bloc, which negotiated the creation of a power-sharing government in the wake of 2008's bloody poll.
With 600 observers on the ground, SADC's verdict will be closely watched by western nations blocked from monitoring the poll themselves.
The bloc said it will deliver its initial verdict later Friday.
Foreign diplomats have expressed deep misgivings about a poll they have described privately as non-violent but fundamentally flawed.
Jeffrey Smith, from the Washington-based Robert F. Kennedy Center for Justice and Human Rights, said it would be wrong to disregard the final results but "we must also not be blind to potential irregularities both leading up to the vote and on the day".
So far Tsvangirai has limited his comments to condemnation of the poll, but already there are calls for mass protests, and warnings that may prompt a bloodbath.
The top brass from his Movement for Democratic Change will meet on Saturday to decide their response.
Ahead of he meeting top MDC official Roy Bennett called for a campaign of "passive resistance".
"I'm talking about people completely shutting the country down -- don't pay any bills, don't attend work, just bring the country to a standstill."
"There needs to be resistance against this theft and the people of Zimbabwe need to speak out strongly."
The disputed outcome risks plunging Zimbabwe -- which battled a decade-long downturn marked by galloping inflation and mass migration -- back into deep crisis.
"If certain people feel their choice was not accepted, they may resort to violence," said Sean O'Leary a spokesman for a 3,000-strong group of poll monitors from the Catholic church.
Investors also expressed fears about the impact of a Mugabe victory, which could roll back the power-sharing government's efforts to stabilising the economy after crippling hyperinflation and joblessness.
"It's back to extreme volatility," Iraj Abedian the CEO of Pan African Investments said from Johannesburg. "We can expect fairly radical positions that will have populist support, but which will have huge implications."
Abedian predicted banks and financial firms could become the targets of a new Mugabe government seeking to extend its programme of indigenisation, after agriculture and mining.
"The land grabs caused chaos in the agricultural sector and it took ten years for it to settle down.
"The financial sector would have a similar impact. It would cause chaos, but ZANU-PF and Mugabe seem to like that."
Mugabe -- Africa's oldest leader -- is a former guerrilla leader hailed as a hero of Africa's liberation movement, guiding Zimbabwe to independence in 1980 from Britain and white minority rule.
But his military-backed rule has been marked by controversial land reforms, a series of violent crackdowns, economic crises and suspect elections that have brought international sanctions and made him a pariah in the West.
As the economy in southern Africa's former bread basket recovers from crisis, Mugabe loyalists insist their hero is "tried and tested" and dismiss concerns about his age and rumoured health problems.
Former union boss Tsvangirai won the first round of voting in 2008, but was forced out of the race after 200 of his supporters were killed and thousands more injured in suspected state-backed intimidation and attacks.
This time around he announced plans to lure back foreign investors, create a million jobs in five years and improve public services in a bid to secure a long-awaited victory.
But some Western analysts said this could be Tsvangirai's last bid at the top job, if the MDC fails to prevent Mugabe sweeping to a seventh term.