Juju calls for polls coalition
Julius Malema, who advocates the nationalisation of mining and land, and the curbing of "white economic power", has called on other opposition parties to unite with his EFF to break the grip of the ruling party at the municipal polls this year.
The persistence of widespread poverty 25 years after apartheid was ended has eroded the ANC's support, especially among voters people born after 1994.
Malema said the weakness of the economy had raised the possibility that the ANC would lose control of Johannesburg and Pretoria at the ballot.
"South Africans must shoot warning shots now, through their votes," Malema said .
"It is an opportunity now for South Africans to show the ANC that they are tired - that the ANC should begin to take them seriously, ahead of the national elections in 2019."
The World Bank has forecast that the South African economy will grow by only 1.4% this year.
Unemployment is put at 25% officially.
Even President Jacob Zuma has forecast a tough fight with the opposition at the polls.
Malema - who points to the JSE stock exchange as a symbol of the capitalism his party aims to dismantle - said the ANC was still relying on the memory of Nelson Mandela to woo votes.
Many older South Africans feel grateful to the ANC for winning their freedom, thus giving the party unbroken power for the past two decades. But surveys show that most people reaching the age of 18 are not automatically joining the ANC, as was one the case.
"The only thing they know is liberation, so they want to tell people about Robben Island," Malema said, referring to the prison in which Mandela was incarcerated.
"To young people, those things do not appeal," said the former leader of the ANC's youth wing, referring to the "Born Free", a generation with no memory of white minority rule.
ANC secretary-general Gwede Mantashe told a press briefing that his party "is confident of retaining all metropolitan municipalities we currently govern and will be fighting to win the City of Cape Town", from where the DA leads the Western Cape provincial government.
The EFF won 6% of the vote in the 2014 general election, the DA 22% and the ANC 62%.