Tsvangirai claimed victory based on early results from the Saturday election defying an earlier warning issued on Friday by the chiefs of defence and security forces.
The MDC leader told British newspaper, The Sunday Telegraph that he had won the election and that President Mugabe should concede defeat.
“Victory is assured in spite of the regime’s attempt to subvert the will of the people,” he added.
Banned international news agencies including the BBC are already reporting news that the MDC is claiming victory.
"If President Mugabe wins this election and the MDC has already claimed victory, there's likely to be chaos in the country. The MDC are thwarting the spirit of fair play and calm that characterised the whole voting process," said a Zanu PF official who refused to be named.
The Secretary General of the MDC, Tendai Biti, also issued a statement saying the MDC had won the election. “It's a historic moment for all of us. We have won this election, we have won this election,” Biti told reporters, diplomats and observers at a briefing a few hours after the poll closed.
Biti’s statement was based on unconfirmed information from his party’s election agents who were sending text messaged saying early results posted at polling stations showed MDC leader Morgan Tsvangirai was projected to win 66 per cent of the vote in the capital Harare.
Biti also claimed that Tsvangirai had won significantly President Mugabe’s rural strongholds.
“This is just a sample of what we are getting from every province. In our view we cannot possibly see a (reverse) of this trend,” Biti said, adding the MDC would announce more results at 0800 GMT.
The Zimbabwe Electoral Commission said it would start to announce official results later on Sunday (local time).
Observers say they are concerned about different announcements of the results. The general instruction only authorises the Zimbabwe Electoral Commission to announce the poll results.
Zimbabwe’s service chiefs have issued a chilling warning that they “are not going to allow a situation where individuals arrogate themselves the role of election officials and announce themselves winners at any stage of the electoral process.”
They added: “The authority of counting votes and announcing the winners is vested in the Zimbabwe Electoral Commission (ZEC) in accordance with law. We warn anyone of such inclination that we will not tolerate any such pronouncements as they have the effect of trying to take the law into their own hands thereby fomenting disorder and mayhem. Everyone is therefore advised to follow the law.”
It is not clear how the chiefs will respond to these announcements by the opposition MDC, but they have warned that, on their part, they “are without doubt ready to carry out our constitutional obligations without fear of favour.”
Efforts to reach Commissioner General of Police, Augustine Chihuri, proved fruitless at the time of going to press.
