The National Prosecuting Authority's conduct in prosecuting ANC president Jacob Zuma will again be scrutinised in court when the Supreme Court of Appeal sits on the matter on Friday.

The Bloemfontein court will hear an appeal by the National Director of Public Prosecutions (NDPP) against a Pietermaritzburg High Court judgment which invalidated the charges it brought against Zuma.

High Court Judge Chris Nicholson held that the State's decision to prosecute Zuma was unlawful because it had failed to take representations from him.

In papers filed at the SCA on Tuesday, Zuma argues that the NDPP in terms of Section 179(5)(d) of the Constitution was obliged to offer him an opportunity to make representations.

Zuma contends there was a clear legal obligation on the NPA to allow him an opportunity to make representations before the December 2007 decision to prosecute him.

In regard to the lower courts findings on political intrusion, Zuma argues that the decisions to prosecute him took place in circumstances which suggested that political considerations and influence from his political rivals were at work.

Especially, at the time of the December 2007 decision there was "significant controversy as to whether the NDPP decisions and conduct in connection therewith were influenced or affected thereby".

Zuma said the High Court did indeed consider whether the facts and circumstances testified to (of political influences) displayed some merit.

"It carefully considered the circumstances and decided that there appeared to be merit in the respondent's (Zuma's) averments of political interference in his prosecution."

Zuma said the high court's findings on the issue were that the allegations could not be struck out.

The ANC president faced a charge each of racketeering and money laundering, two charges of corruption and 12 charges of fraud related to the multi-billion rand government arms deal.

Officials at the Bloemfontein court said security at the SCA would be very tight. A huge media contingent was also expected.

The African National Congress in the Free State said thousands of members would again be attending court proceedings involving Zuma.

Free State ANC spokesperson Teboho Sikisi said the party had applied for permission to hold a rally in front of the court on Friday.

"... something along the lines of what happened during the last court appearance," he said.

Sapa