Johannesburg - Zimbabwe's prime minister-designate Morgan Tsvangirai warned he would break off all negotiations with President Robert Mugabe's Zanu-PF if dozens of his party members and activists that have been abducted by suspected state agents were not released.

Tsvangirai put at 42 the number of people from his Movement for Democratic Change (MDC) and civil society activists, including Zimbabwe Peace Project director Jestina Mukoko, that have been detained by police or suspected intelligence agents in recent weeks and since disappeared.

Addressing a press conference in Gaborone, the capital of Zimbabwe's neighbour Botswana, where he has been in exile for weeks, Tsvangirai said: "If these abductions do not cease immediately, and if all the abductees are not released or charged in a court of law by January 1, 2009, I will be asking the MDC's National Council to pass a resolution to suspend all negotiations and contact with Zanu-PF."

"There can be no meaningful talks while a campaign of terror is being waged against our people," Tsvangirai said.

Mugabe, Tsvangirai, and another opposition leader Arthur Mutambara, signed a deal in September to share power but the agreement has yet to be implemented as Zanu-PF and the MDC fight over positions.

Tsvangirai repeated that the MDC "will only enter into an agreement that enables us to participate as an equal partner."

Mugabe is currently insisting on keeping the lion's share of power for his party, including control of the army and shared control of the police, although the MDC won the last general elections.

Tsvangirai's remarks put paid to South African President Kgalema Motlanthe's prediction that a unity government could be in place by the end of the week.

If Zanu-PF and the MDC could not agree on an equitable division of power, Tsvangirai said "an internationally supervised presidential election must be conducted in an environment that is conducive to a free and fair poll."

Mugabe has also floated the prospect of fresh elections because of the impasse, but analysts say elections called by Zanu-PF on its terms are likely to be violent, like the June presidential election run-off that Tsvangirai boycotted.

Zimbabwe is in the throes of an acute humanitarian crisis, including a cholera outbreak that has killed over 1,000 people since August.

In an apparent bid to divert attention from the crisis, Mugabe's government has accused the MDC of plotting, together with Botswana, to overthrow his regime.

Botswana and the MDC have rejected the allegations, and South Africa's Motlanthe also said the Southern African Development Community (SADC) felt they were to be taken "with a pinch of salt."

Tsvangirai called on SADC to stop pressuring the MDC to join a government on Mugabe's terms and to work more closely with the African Union and the United Nations to resolve the impasse.

SADC's mediator in Zimbabwe, former South African president Thabo Mbeki, is a longtime ally of Mugabe's. (dpa)