Harare — SOUTH African President Thabo Mbeki plans another visit to Harare in a bid to revive talks that collapsed last week when President Robert Mugabe rejected opposition demands for a new constitution and a postponement of elections scheduled for March.

With the breakdown of the talks attracting more criticism of his "quiet diplomacy" approach to the Zimbabwean crisis, the South African leader at the weekend reportedly told his negotiating team, led by Sydney Mufamadi, that it was crucial to return to Harare "sooner, rather than later".

"He told (his senior adviser Reverend Frank) Chikane in front of us that there was an urgent need to return to Harare in the next week due to the sharp differences between the two camps," said a source.

"He has indicated to both parties that he wants to exhaust all available avenues before he can consider officially declaring a deadlock to SADC (the Southern African Development Community)."

Mbeki has on several previous occasions reported to SADC that progress was being made but he now finds the process bogged down by arguments over the timetable for elections and the introduction of a new constitution.

President Mugabe argues his opponents are not ready for the polls, which he has set for March, and that a referendum - and not a committee of leaders from both sides as suggested by the MDC - must decide on the new constitution.

The MDC says March is too soon to hold elections, pointing out more time is needed to allow the implementation of agreements reached so far.

One of the areas of contention is the MDC's demand for the re-constitution of the Zimbabwe Electoral Commission, which runs the country's elections.

The MDC charges that ZANU-PF has stuffed the ZEC with loyalists so it can rig the elections.

Last Thursday, "after two hours of lunch and two hours of talks on the matter and other issues outside the talks", according to a government source, President Mugabe told Mbeki there would be no negotiation with the MDC on the two outstanding matters.

Emerging from that meeting, Mbeki put on a brave face, telling journalists he remained optimistic the talks would eventually succeed.

"I am confident the dialogue will be successful. I have listened to the views of both sides and will continue with this process," he said.

But government sources said he had found President Mugabe unyielding with regard to opposition demands.

"President Mugabe told Mbeki there was no way he could implement a new constitution when the opposition rejected a new constitution in the 2000 referendum," said a government official familiar with the talks.

President Mugabe wants the MDC to exert pressure on "its Western allies" to immediately lift personal sanctions imposed on senior government officials, which ZANU-PF repeatedly blames for the economic meltdown.

But the opposition has dug its heels in on the matter, insisting it has no authority over the European Union parliament and the United States Congress, which imposed the measures.

The MDC is said to have asked Mbeki to refer the impasse to the SADC troika on politics, defence and security, which is chaired by Angola.

Tendai Biti, one of the opposition negotiators, said the MDC would wait to hear from Mbeki before deciding on the next course of action.

Eldred Masunungure, a political analyst who has been closely following the talks, said the deadlock between ZANU PF and the MDC was another fatal blow to Mbeki's much-vaunted quiet diplomacy.

Sources closely following the talks said the Morgan Tsvangirai faction of the MDC was reneging on earlier assurances it had made to Mbeki for fear of losing its allies within the civic society movement that are for a new constitution.

"Is it not ironic that the MDC is pressing for a new constitution before the elections after having agreed to the 18th Constitutional amendments? Why didn't they push for a new constitution from the onset that incorporates the harmonisation of the elections and an expanded parliament?" asked a source.

Yet others said the MDC had agreed to the amendments as a confidence-building measure that was to soften President Mugabe into accepting a wholesale overhaul of the country's Constitution.