South Africa"s largest opposition party won mayoral posts in three major cities in the country"s economic heartland, a blow to the governing African National Congress (ANC) in the wake of its worst-ever election result. Mayoral candidates from the ANC"s main rival the Democratic Alliance (DA) won in the three metropolitan areas up for grabs in the country"s most populated province of Gauteng: Johannesburg, Tshwane which includes the administrative capital Pretoria and Ekurhuleni, where the busiest airport is located. However, DA victories were made possible by the support of the Marxist Economic Freedom Fighters (EFF), led by firebrand Julius Malema, and ActionSA, led by a former DA mayor of Johannesburg who broke away from the party. There seems little to unite them beyond their common enemy. The DA, for instance, has struggled to shake off its image as a party of white economic privilege, while the EFF argues for radical economic policies like the nationalisation of land and the central bank. In municipal elections early this month the ANC"s overall support dropped below 50% for the first time since the end of white minority rule, and its share of the vote in big cities like Pretoria and Johannesburg slid to roughly one-third. read more The smaller opposition parties voted for the DA candidates despite negotiations between them failing to reach coalition agreements. That means the DA mayors will be beholden to the EFF and ActionSA to support their initiatives, and they could be voted out at short notice if relations turn fraught. A previous partnership between the DA and EFF broke down. DA leader John Steenhuisen, who during the election was adamant he would do no deal with the EFF, told reporters his party"s victories meant a psychological threshold had been crossed. "Today the whole of South Africa knows that the ANC can be beaten," he said. ANC spokesman Pule Mabe did not respond to a request for comment, but the ANC in Johannesburg has congratulated the DA"s incoming mayor and said it would hold her administration accountable. ActionSA said its support for the DA was motivated by a desire to keep the ANC out of power and it was now up to the DA to return to the negotiating table if it wanted stable local governments.