The latest round of power-sharing talks, at a regional security summit in Harare, broke up early on Tuesday morning with the parties still deadlocked over the allocation of ministries in a coalition government.
"Mbeki will not stand up to Mugabe," said a source very close to the negotiations.
He pointed out that opposition leader Morgan Tsvangirai was still being denied a passport by the Zimbabwean authorities. "If you can’t force Mugabe to give Morgan Tsvangirai, who is the prime minister designate, a passport, then you can’t force him to do anything."
He added that the new South African president Kgalema Motlanthe – who attended the talks and who Western diplomats had hoped might bring with him a change of approach – would "never go against Mbeki," saying that both men were too distracted by political upheavals at home in South Africa to give the crisis in Zimbabwe their full attention.
Mr Mugabe, 84, who has a long history of out-manoeuvring his political opponents, appears to be exploiting events to his advantage.
The key question holding up the new government is control over the ministry of home affairs, which has authority over the police. Mr Tsvangirai has agreed that Mr Mugabe’s Zanu-PF keep control of the army and intelligence services, but has insisted the MDC be given home affairs, which the president unilaterally allocated to his own party.
The process has become a test of the much-vaunted concept of "African solutions for African problems". The summit communiqué said it "strongly encourages the parties to pursueco-operative management" of home affairs, but joint control, with two co-ministers, would open the way for Zanu-PF to abuse the situation.
Arthur Mutambara, the minority MDC leader and a signatory to the power-sharing agreement said yesterday his party fully backed Mr Tsvangirai being given the home affairs ministry.
Tendai Biti, the MDC secretary-general and chief negotiator, admitted that they had been naive to sign the power-sharing agreement last month.
The MDC had done so in a sprit of "trust, goodwill and faith" he said. "Now we have learned we cannot leave anything to chance. Zanu-PF is not sincere."
He said that the agreement presented to the world on Sept 15 had been altered from the one signed a few days earlier, and that the changes were more than "typographical errors." The document, Mr Biti said, was produced by the government printers and was a "Frankenstein monster".
"A marriage like this agreement needs courtship before consummation. So, don’t throw bricks at us, send us flowers and invite us to dinner first," he said. "We want an equitable distribution of top positions, including ministries, permanent secretaries, diplomatic postings and a fair share of provincial governor positions."
The MDC deprived Zanu-PF of its parliamentary majority in the March elections and Mr Tsvangirai easily beat Mr Mugabe in the first round of the presidential election, but pulled out of the run-off citing violence against his supporters.
The talks will now move to a full summit of the Southern African Development Community, but Mr Biti warned that Mr Tsvangirai will not attend if it is held outside Zimbabwe, unless he is given the passport that he applied for in June.
A source close to the talks said the power-sharing agreement was "teetering on the point of collapse".
"Perhaps it can be rescued if SADC leaders as a bloc tell Mugabe to back down on the home affairs ministry," he said. "The problem is there is nothing else but this agreement." The Telegraph (UK)