Kamogelo Seekoei, Tebogo Monama, Getrude Makhafola and Sapa
The South African Tourism Services Association (Satsa) said Eskom's power cuts put the 2010 soccer World Cup at risk.
Chief executive Michael Tatalias said cuts this winter, when demand peaks, would show if the country could host the World Cup.
"If Eskom fails to keep the lights on this winter as demand goes up, then we will have bigger problems come 2010," he said.
"We are hoping to have more than 300000 visitors, all using electricity. The stadiums may have all the most wonderful generators in the world to broadcast the games, but will people come to South Africa to see [the games] if they know they will be going back to hotels and guest houses with no power?" asked Tatalias.
He said massive building projects for 2010 were on tight deadlines and needed huge amounts of power.
"The building work on the stadiums is also going to be widely disrupted. We have to ask ourselves honestly if we can still do this."
"This is not Eskom's problem alone, government must also help. There will be a rise in fuel and gas consumption and they must make these available.
"We can't have a shortage of electricity and fuel at the same time," he said.
"Ready or not, 2010 is coming. All we have to do is make sure that we are ready when it arrives. The public should also be responsible in their electricity usage."
The South African Football Association's chief executive Raymond Hack said: "I have no fear that we are capable of hosting the World Cup.
"People are going to come to the country to watch football and they are going to watch brilliant football."
Tim Modise, spokesman for the 2010 Local Organising Committee, said they also had no fears of hosting the tournament.
"We have generators and power cuts have affected us, but we are not behind schedule with the construction of stadiums.
"We are meeting Eskom in the next couple of days to establish the way forward. If a problem happens now and we resolve it, I do not see how it will still be a problem when 2010 comes."
But Eskom has repeatedly said the problem will persist for at least five to eight years.
The government's Tourism South Africa said it was unfazed by Satsa's statement.
Spokesman Monde Mateza said Satsa represented the private sector. He said the effects of power outages were not yet quantifiable.
Tatalias said the power cuts could destroy South Africa's tourism industry.
"The industry will take a huge financial knock this year. So far little attention has been paid to the effects of continuing power outages on the tourism industry, and it will be badly affected."