Forty percent of the 12,791 people polled approved of Zuma's performance, but 51 percent said he was not a capable president. The rest were unsure how to rate him.

The survey also found that there were strong racial differences in opinion, with black respondents being most positive.

The respondents were from across the country and were all aged 18 to 34. The survey was conducted by Pondering Panda.

Most coloured, white and Indian youth did not approve of Zuma, the survey found.

However, in KwaZulu-Natal, 54 percent of respondents felt Zuma was a suitable leader.

In a separate survey, 60 percent of the youth said they would definitely vote in the country's general elections in 2014. Twenty-eight percent said they "wouldn't bother".

Pondering Panda spokesman Butch Rice said the results of the two surveys were alarming.

"Previous surveys have shown that Zuma has lost credibility with the youth when it comes to delivering on promises of jobs and education. We now see that they also feel he is generally incompetent," he said in a statement on Monday.

"If he remains the ANC's presidential candidate for the next election, it could cost them dearly. The results of these surveys show that voter turnout will be key to political party success in 2014."