The African Union (AU) and the regional SADC bloc have been urged to prepare to intervene in what is being predicted as potential post-election chaos in Zimbabwe.

As Zimbabweans across the country were busy casting their votes on Wednesday, concern remained high that the process would not result in a credible outcome.

This was the prediction by the International Crisis Group, which warned this week that Zimbabwe was on the brink of a 'protracted political crisis'. The group, in a new report released two days before the poll, listed the possible outcomes of the elections. They warned that none of the outcomes will result in the change Zimbabweans are hoping for.

The Group said the least likely outcome was an uncontested victory by either of the MDC parties contesting, or by ZANU PF. The think tank predicted the following outcomes:

- ZANU PF wins a deeply flawed election that is accepted by most in the interest of avoiding violence and further economic chaos;

- ZANU PF wins a deeply flawed election that is accepted by SADC/AU observers, but not by MDC formations and civil society, leading to further political impasse and economic deterioration;

- ZANU PF "wins" a clearly rigged election; the courts give no remedy, leading to large protests, repression, political isolation and economic deterioration; or

- MDC-T wins at least in the first round, provoking a backlash by hardliners/securocrats to prevent a transfer of power.

"Other scenarios are also possible, but whatever ultimately transpires, it will become more precarious if the presidential contest again goes to a second round. Most projected outcomes suggest a strongly disputed result. In that event, resolution mechanisms may not provide a legal remedy, and African facilitation may be required to either rerun elections after several months of careful preparation or, if that is not possible, secure a political solution involving a negotiated reconfiguration of power sharing," the Group's report states.

The Group said that SADC and the AU should be prepared to declare the results illegitimate and press for the elections to be run again after a minimum of three months. In this interim period, the African leadership bodies and the AU should continue to recognise the current GPA power-sharing administration as the legitimate government.

"If new elections are held after October 2013 -- the constitutional deadline in view of the end of June dissolution of the Parliament, or the parties prefer to avoid elections for the time being, either an extension of the current arrangement or negotiation of a reconfigured power-sharing deal -- described by some as 'GPA 2'-- would be required," the report said.

It added: "If the government refuses, SADC and the AU should consider such options as non-recognition, suspension of membership and targeted sanctions to enforce compliance."