The troubled Zimbabwe negotiations which have still not resolved the  main issue, who will have executive power in any power sharing deal,  entered its final day Tuesday. Peta Thornycroft reports that the mediator of the talks, South African President Thabo Mbeki is due back in South Africa Wednesday.

There is still a long list of fundamental issues to be negotiated  before any deal between President Robert Mugabe and opposition leader  Morgan Tsvangirai can be signed.

Among the outstanding issues is how Tsvangirai would be appointed prime minister, by Mr. Mugabe or by  parliament.

The talks also have not addressed how long an inclusive interim government would be in power before a new constitution is agreed upon followed by new elections.

In addition, it has not been decided how many of the 10 positions of  powerful provincial governors would go to Tsvangirai's Movement  for Democratic Change and how many to Mr. Mugabe's ZANU-PF.

Many lesser but still fundamental issues have yet to be decided. For example, who would control the public sector organizations which appoints civil servants and judges.

The number of cabinet posts has largely been agreed and they would be split evenly between the opposition allies and ZANU-PF

The fundamental question of who will hold executive power was not addressed by the six negotiators in South Africa during two weeks of  talks prior to this round in Harare.

Mr. Tsvangirai was to be the prime minister and Mr. Mugabe the  president, but the power attached to each position has not been agreed upon.

ZANU-PF sources say Mr. Mugabe had hoped the deal would be signed on Sunday and that the parliament would be called on Wednesday.

Mr. Mbeki was appointed by SADC to mediate the Zimbabwe crisis after  Tsvangirai and scores of his officials were assaulted in police custody in March last year.

Tsvangirai maintains that the opposition not only won control of  parliament but that he won the presidential election in the last  relatively free and fair poll in March. He did not contest the presidential run-off in June because of  violence against his supporters.

Mr. Mugabe was then sworn in for an additional five year term because he was the sole candidate in a second round on June 27. His election was not  recognized by any of the African observer groups.

There is agreement by both ZANU-PF and MDC that an inclusive  government is needed to bring Zimbabwe out of its economic chaos.

Whether it will come now or perhaps at a further round of  negotiations is not clear.