Former South African president and Zimbabwe crisis mediator Thabo Mbeki launched back into brokering the country's power-sharing process on Tuesday, holding talks with the principals of the long-ruling ZANU-PF and the former opposition Movement for Democratic Change.

Mr. Mbeki held a brief meeting at the Rainbow Towers hotel in Harare with negotiators for the three parties before meeting President Robert Mugabe, prime minister-designate Morgan Tsvangirai and deputy prime minister-designate Arthur Mutambara.

Tsvangirai and Mutambara lead rival MDC formations.

Briefing journalists before entering the talks venue, Mutambara expressed frustration saying the fact the leaders were there to seek mediation was “a travesty of justice.”

He continued saying, “Mutambara, Mugabe and Tsvangirai should shape up or ship out."

But Mbeki expressed optimism that he can bring the parties to agreement on the composition of the cabinet for the national unity government envisioned in the power-sharing agreement signed on Sept. 15.

ZANU-PF insiders told VOA that he started the process with one-on-one talks with each of the principals. They said Mbeki's talks agenda focused how to share cabinet posts equitably, and would also cover the appointment of governors for Zimbabwe's 10 provinces.

The officials said ZANU-PF wants Mbeki to revisit language in the agreement which suspends parliamentary by-elections for one year to avoid inter-party clashes.

Speaking from Cape Town, South Africa, political analyst Glen Mpani told reporter Blessing Zulu of VOA's Studio 7 for Zimbabwe that Mugabe’s intransigence is explained by the serious internal divisions he faces within his party over power-sharing concessions.

More reports from VOA's Studio 7 for Zimbabwe...