Since the power-sharing agreement was signed in September it has been hamstrung by disputes over the distribution of ministries, which Mr Mugabe allocated unilaterally, leading to fears he will dominate the new structure.
In the meantime, the country’s implosion has continued, with hyperinflation independently estimated in the sextillions, millions in need of food aid, and hundreds dying of cholera.
The former United Nations secretary-general Kofi Annan, the US ex- president Jimmy Carter, and Graca Machel, Nelson Mandela’s wife, had planned to go on a fact-finding mission to Zimbabwe, but Mr Mugabe’s government made clear they were not welcome.
After three days of meetings in Johannesburg, they said the humanitarian crisis was worse than they ever expected, and now so urgent that a resolution of the political deadlock was imperative, as the two went hand-in-hand.
"Politicians have a way of playing little games and nitpicking sometimes over issues that are not that important in the scheme of things," said Mr Annan.
The trio had met with both the MDC leader Morgan Tsvangirai and Arthur Mutambara, the head of a breakaway opposition faction, he said.
"We have indicated to them that the most important issues are the lives and the suffering of the people and that must be paramount. I hope they will draw the right conclusions and move expeditiously to form a government."
Mr Carter pointed out that the MDC’s parliamentary majority would be a safeguard and Mrs Machel said: "It should not be impossible for the leaders of Zimbabwe who claim they are concerned for the people to come together and work for the people and we have not seen that."
The Elders also condemned Mr Mugabe – Mr Carter referred to the "so-called government" in Harare, adding: "He doesn’t want to admit there’s a need for assistance" – and the regional Southern African Development Community for failing to be more assertive in the past.
Earlier, Jacob Zuma, the leader of South Africa’s ruling ANC, and Kgalema Motlanthe, the country’s president, also pressed the MDC.
"I think it’s now an urgent matter because people are dying," said Mr Zuma, pleading with all parties to "exercise their leadership responsibilities".
In a clear reference to the MDC, Mr Motlanthe added: "In this kind of situation once parties are comfortable and not willing to take the bold step and take responsibility, the tendency is for them to start parallel processes."
But the opposition insists that no deal is better than a bad deal and said several issues remained outstanding.
"As far as we are concerned we have not yet arrived at the point where there is equitable power-sharing so at this point the MDC can’t be part of a government," said Mr Tsvangirai’s spokesman George Sibotshiwe. The Telegraph