Zimbabwe's former president Robert Mugabe, who was ousted in November, has said he would not vote for his successor Emmerson Mnangagwa in the presidential election. He said he resigned to avoid "bloodshed".
Both Chamisa and Mnangagwa have vowed to rebuild an economy shattered by Robert Mugabe's long rule.
Monday's election is being seen as a major test for the ruling ZANU-PF party. During the address, he also addresses rumors that he planned to have his wife, Grace Mugabe take over, calling them "utter nonsense". "I will make my choice among the other 22 (candidates) but it is a long list", he added at a press conference in Harare.
"Whoever wins, we wish him well ..."
Mr Mugabe added that, since he was forced from office previous year, "the people of Zimbabwe have not been free".
"The sudden & arbitrary withdrawal of security details from President Mugabe's residency after he said he is voting for #NelsonChamisa; not for his "tormentors" proves ZIMBABWE IS NOW UNDER ARBITRARY RULE".
Nicknamed "the Crocodile" for his guerrilla activities during the war for liberation and for years Mugabe's enforcer, Mnangagwa has tried to cast himself as a reformer with pledges of a free and fair election after past votes were marred by violence and irregularities. There are 23 candidates on the presidential ballot.
Parliamentary and local elections will run alongside votes for the presidency. It also faces high youth unemployment rates and since most of the registered voters are below 40 years, the electorate will focus most on candidates whose agenda leans more towards creation of jobs.
He has survived several assassination attempts blamed on supporters of Mr Mugabe.
He is known for his wit and humour, and as a lawyer and a pastor his rallies and news conferences have taken on the fervour of a revivalist campaign.
The former student leader has won over many young and unemployed voters who are exhausted of the governing Zanu-PF. It was only the second of two opinion polls.