Zuma is accused of accepting bribes from a French arms manufacturer and his former financial adviser.
 
He faces trial for corruption, money-laundering, fraud and racketeering in South Africa's highest court.

He is expected to succeed Thabo Mbeki as South Africa's next president - Mbeki must step down by 2009 - but a guilty verdict could end his presidential hopes.

Presidency in jeopardy

The trial against Zuma is due to begin in August but if the right to an appeal is granted, his legal battles could spill over to the presidential election period.

Zuma has said he would bow out if convicted.

"This is the end-game for Zuma. It is his last gasp in an attempt to avoid a corruption trial," according to Nic Borain, a political analyst.

South Africa's supreme court of appeal had ruled in November 2007 that documents seized by an elite crime-fighting unit could be used against Zuma during his trial.

The appeal court had also opened the way for South African prosecutors to use documents seized from Mauritius, said to contain evidence of bribes being solicited on behalf of Zuma, in return for using his influence in a government arms deal.

Payments suspended

Meanwhile, the South African government suspended further payments of legal costs to Zuma over his impending corruption trial.

Aletta Mosidi, the head of the state attorney's office, said that the government would not pay Zuma's future legal costs until he provided a detailed account of how he had spent the $1.1m that he had received earlier from the state.

"We have to be accountable to the treasury and the auditor-general about how the taxpayers' money was being spent. It is not that we are unprepared to pay Zuma's legal costs, but we cannot do so without a definite idea of how we are being charged and what we are using the state money to pay for," Mosidi said.

Zuma, who toppled Mbeki from the helm of the ruling party in December, has repeatedly denied any wrong-doing and said the charges against him were politically motivated.

Relations between Zuma and Mbeki had been strained over the last few months and the power struggle between the two men had stirred concerns of instability in South Africa.