South African-mediated Zimbabwe crisis negotiations were set back on the weekend as representatives of the ruling ZANU-PF failed to show for a follow-up round of talks and President Robert Mugabe rejected a proposed constitutional overhaul.

Sources close to the Pretoria talks mediated by South African President Thabo Mbeki said Zimbabwean Justice Minister Patrick Chinamasa and Labor Minister Nicholas Goche did not turn up for the resumption of the talks as scheduled.

Representatives of both factions of the opposition Movement for Democratic Change, present in Pretoria for the expected round of talks, returned to Zimbabwe.

Meanwhile, Zimbabwe state media said President Mugabe told supporters that there was no need for a new constitution. State television quoted Mr. Mugabe as saying the present constitution ?serves the nation well? so there is no reason to change it.

His ruling party has submitted legislation to parliament providing for a number of major changes to the constitution, most of which would strengthen its hand electorally.

International Relations Secretary Eliphas Mukonoweshuro of the MDC faction headed by MDC founder Morgan Tsvangirai told reporter Patience Rusere that developments show a lack of seriousness by the ruling party in the negotiating process.

Cape Town-based political analyst Hermann Hanekom said that Mr. Mugabe has only agreed to take part in the talks to buy time with the international community.

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