Johannesburg: South Africa's ruling ANC, in its strongest criticism of President Thabo Mbeki yet, yesterday warned of a "dire" situation in Zimbabwe which was having a negative impact on all of southern Africa.

Mbeki, who has long pursued "quiet diplomacy" in Zimbabwe and adopted a wait-and-see approach after the poll, said before a summit of the Southern African Development Community (SADC) at the weekend he saw no crisis in the neighbouring country.

A statement by the ANC's executive National Working Committee said it "regards the situation in Zimbabwe as dire, with negative consequences for the SADC region".

It called on the Zimbabwe Electoral Commission, which has failed to release the results of the March 29 presidential poll, to announce the outcome "without further delay", adding, "to hold a run-off vote when the election results are not known would be undemocratic and unprecedented." The ANC committee said Mbeki, defeated as ANC leader by Jacob Zuma last December, must remain neutral as a regional mediator.

Zuma is likely to succeed Mbeki when he steps down next year. Relations between the two men have been frosty since Mbeki sacked Zuma as his deputy in 2005.