The incumbent President Robert Mugabe, who has been in power since Zimbabwe's independence in 1980, is challenged by Tsvangirai and former finance minister Simba Makoni, who was expelled from ZANU-PF after throwing his hat into the ring.
Mutambara did not run for presidency and supported Makoni's bidding.
Analysts are projecting that the pattern of results for the House of Assembly election is indicating that none of the presidential candidates can win a 51 percent majority in the first round of voting, making a run-off an imminent possibility.
Senatorial, local government and presidential results are still to be announced.
(Xinhua News Agency April 3, 2008)
