Johannesburg - The 2014 general elections could see the lowest voter turnout since democracy was established in 1994, the City Press reported on Sunday.
The newspaper reported that 46% of eligible voters were likely to not turn up at the polls.
This possibility was suggested both by the fact that 10 million eligible voters had not registered, and the IEC's expectation that only about 70% of those registered would actually take pen to ballot papers on Wednesday.
Twenty five million people are registered to vote this week.
A total of 42% of eligible voters skipped the elections in 2009.
A poll conducted last month by market research company Ipsos found that 42% of those who had not registered would have voted for the ANC, followed by 8% who would have supported the DA and 4% who would have favoured the EFF.
Ipsos said most of the unregistered voters polled gave their reason for not taking part in the election as being because they felt their vote would make no difference.
The African National Congress spokesperson Keith Khoza said the number of unregistered voters would not impact on support for the ANC.
"Those votes weren't ours in the first place," he said.
Economic Freedom Fighters spokesperson Mbuyiseni Ndlozi said the Ipsos numbers were "wrong" as they suggested the majority of unregistered voters were youth.
"The express majority of those who have turned out to register are... between 18 and 34."
The Democratic Alliance's Gauteng premier candidate Mmusi Maimane said the unregistered voters could have "swung the vote".
"They should have been at the forefront of these elections," he told the City Press.