Mugabe and Tsvangirai were speaking at a conference of political parties and civil society groups reviewing the proposed new constitution in Harare.

Mugabe's Zanu-PF wants to overhaul some provisions of the constitution that would limit presidential powers while strengthening those of parliament.

Tsvangirai's Movement for Democratic Change accuses Zanu-PF of retaining power through vote rigging and violence.

The final draft of the charter is likely to be compromised because neither party commands the two-thirds majority required to railroad it through parliament. The first conference on the constitution, three years ago, was disrupted by political clashes.

"We must live up to the expectations of the people of Zimbabwe. Let us be peaceful in our conduct. Surely, settling things through fisticuffs instead of through dialogue and discussion is primitive," said 88-year-old Mugabe, who wants to extend his 32 years of rule.

Mugabe said the next poll would be in March but his opponents are pressing for more reforms to avoid election disputes.

Tsvangirai called for calm but contradicted Mugabe's suggestions that the two of them would have the final say on the draft - a position also at odds with a decision taken by the inter-party parliamentary committee driving the constitutional reforms.

Though Mugabe struck a conciliatory tone, describing his coalition with Tsvangirai and a smaller MDC faction as "an unholy trinity that has done some holy things", the prime minister took aim at some Mugabe allies who have been quoted as suggesting that the army would not accept a Tsvangirai poll victory.