JOHANNESBURG (Reuters) – Jacob Zuma called for a huge turnout for South Africa's election on Wednesday to give his ruling ANC an overwhelming mandate in its toughest test since the end of apartheid.

Zuma is expected to become president after the ballot, but the African National Congress risks losing the two-thirds majority in parliament it needs to change the constitution.
A big turnout could strengthen Zuma's mandate in the face of a challenge from a new opposition party formed by ANC dissidents and after the dropping of corruption charges against him on a technicality earlier this month.
Zuma appealed to the 23 million voters to turn out in large numbers and give the ruling party an overwhelming majority.
“We anticipate a massive turnout and we expect that the people of this country will once again give the ANC a huge and decisive mandate to work together with them to further improve their lives,” he told a last news conference before the vote.
He declined to comment on his potential cabinet, whose line-up is being closely watched by markets keen to see Finance Minister Trevor Manuel retaining a strong role.
One political source said ANC bosses wanted Manuel, who has won the respect of international investors for his conservative approach to fiscal policy, to stay at the post for two years.
“They need another two years to train up somebody,” said the source, who did not wish to be named.
Foreign investors and local businesses are worried Zuma may veer away from policies credited with delivering years of economic growth because he owes his rise to forces such as the trade unions on the left of the party.
Zuma has given assurances there will be no dramatic change of direction, and his room for maneuver is also limited by the heavy impact of the global financial crisis on Africa's biggest economy.
Opposition parties have been trying to capitalize on growing frustration with poverty, crime and AIDS, as well as doubts about corruption.
But analysts say they are very unlikely to derail the highly organized ANC, which continues to exert an emotional tug over many voters as the party that ended white-minority rule in 1994.
Although it appears to be hard-pressed to get the nearly 70 percent of the vote it won in 2004, many political analysts see the ANC winning between 60 and 66 percent of seats in the 400 seat parliament.
One new threat comes from the Congress of the People, formed by ANC politicians who broke with the party after it ousted former President Thabo Mbeki last year over accusations he meddled in a graft case against Zuma, his rival.
Investors could welcome a reduction in the size of the ANC's majority because it would limit its ability to make sweeping changes. Zuma has said the ANC has no plans to change the constitution at the moment.