The leader of the governing ANC in South Africa, Jacob Zuma, is due to address a final election rally of up to 200,000 supporters in Johannesburg.
The African National Congress is facing its biggest challenge for 15 years in Wednesday's polls, although Mr Zuma is still expected to become president.
ANC leader Jacob Zuma has got the unequivocal backing of his party and key allies in the trade union movement and the communist party.
But the ANC is facing more opposition than it's ever had before.
The Congress of the People (COPE), made up largely of former ANC members, has changed the political landscape.
The latest opinion polls indicate COPE could get as much as 15% of the national vote.