Deputy President Jacob Zuma now has no choice but to testify before the Hefer Commission of Inquiry since he has been implicated by just about everyone, the Democratic Alliance said.

In a statement on Sunday DA MP Sheila Camerer said the commission would have no credibility if Zuma did not appear, and Zuma's involvement in the seemingly unauthorised retention of a database of spy information needed to be clarified.

"Deputy President Zuma is the only person able to corroborate the testimony presented to the commission. He has repeatedly bemoaned the fact that he was never granted the opportunity to state his side of the story; what better platform is he waiting for?" Camerer said.

The commission might be issuing its first interim report on spy allegations made against the National Director of Public Prosecutions, Bulelani Ngcuka, this week.

The report will follow the wrapping-up of the evidence given by former transport minister Mac Maharaj and former ANC intelligence commander Mo Shaik.

Maharaj and Shaik were branded as the accusers at the commission after they supported a City Press article claiming that Ngcuka was investigated for being a spy.

President Mbeki set up the Hefer Commission, chaired by retired acting chief justice Joos Hefer, after the article was published in September. At the time Mbeki asked for a report to be made to him "within a month or as soon as possible".

Zuma's office would not comment on the latest call for him to testify, saying that was an ANC matter. But in statements this week, the ANC maintained that there was no need for Zuma to testify and that all ANC files had been handed over.

Meanwhile, the South African National Editors Forum (Sanef) has called "for an immediate withdrawal of the calling of journalists to testify and provide documentation" after learning that the commission intends to subpoena and request more journalists to give evidence.

They include Mathatha Tsedu, Mondli Makhanya, Elias Maluleke and Joe Thloloe.

During a Sanef national council meeting, Sanef chairperson Henry Jeffreys said the move would "violate a prime principle of journalism relating to the respect of the sanctity of documentation, sources and confidential information obtained by journalists in the course of their work". Jeffreys said the latest actions of the commission would undermine the ability of the media to perform its task in society.

It could also set a damaging precedent for the abuse of journalists and their sources.

"Journalistic independence is critical to maintain the free flow of information which is the oxygen of a vibrant democracy," he said.

Former Sunday Times journalist Ranjeni Munusamy is on Monday to appeal against a Bloemfontein High Court ruling which compels her to testify before the Hefer Commission.

Her appeal would be filed at the Constitutional Court, said Jude Mathurine, an advocacy officer at the Media Instituteof Southern Africa.

He said his organisation, Sanef, the Freedom of Expression Institute and the Media Workers Association of SA would act as friends of the court if leave to appeal was granted.

"It is about Ranjeni but more important it is about (defending journalistic) principles," said Jeffreys.

Munusamy passed on her information on Ngcuka to City Press after the Sunday Times, then edited by Tsedu, refused to publish it.

Earlier on Saturday, human rights lawyer Advocate Gilbert Marcus, SC, said journalists must fight hard against efforts to force them to testify before courts or commissions of inquiry.

Marcus said reporters should refuse to testify as a first resort at the Hefer Commission. Judge Joos Hefer should call the people who made the allegations, not the people who reported on them.

Munusamy passed on information about the claim against Ngcuka to the City Press, which published the report that resulted in the Hefer Commission. Several editors have expressed concern about Munusamy's conduct, saying it was unethical.

Others said she acted as a source, not a journalist, when she passed on the information and should therefore be willing to testify.

Marcus has urged them to stand with Munusamy - irrespective of her behaviour - to avoid setting a bad precedent.

Hefer ruled that Munusamy should testify but can object to answer certain questions. She should, however, motivate her objections.

The Bloemfontein High Court upheld the Hefer ruling. Some editors said the court ruling took journalism a step back.

With acknowledgements to Sapa and the Pretoria News.