The axed head of the National Prosecuting Authority, Vusi Pikoli, will testify before the parliamentary committee probing his dismissal next Tuesday, the panel decided on Wednesday.

It will hear submissions from the presidency on the following day as to why President Kgalema Motlanthe fired Pikoli in December after his name was cleared by the Ginwala commission.

The chairman of the committee, Oupa Monareng, told members its task was simply to review whether Motlanthe had acted within his powers and in accordance with the constitution.

"We are not going to reinvent the wheel. We are not a commission but an ad hoc committee," he said.

"We only have to endorse or reject the decision of the president of the republic."

Opposition parties said they expected the ANC-led committee to rubber stamp Motlanthe's decision to sack Pikoli, and predicted the former prosecutions chief would then go to court to challenge his dismissal.

"They are going to drive it through but we are going to fight it," said Koos van der Merwe, the chief whip of the Inkatha Freedom Party.

The Ginwala commission found that Pikoli, who was suspended by former president Thabo Mbeki in 2007, was fit to hold office but Motlanthe refused to reinstate him.

The president cited concerns that Pikoli had put at risk national security when he moved to prosecute national police chief Jackie Selebi for corruption.

Steve Swart from the ACDP said having due regard for national security could not serve as a criteria for an NPA boss' fitness to hold office because it was too vague.

"The state president's view is not defensible from a legal or constitutional basis," he said.

Both Swart and Van der Merwe slammed plans by the ANC to review the NPA Act to determine whether final authority to prosecute somebody rests with the prosecuting authority, the justice minister or the presidency.

The move was announced a day after the NPA won its appeal against the High Court ruling in September to scrap fraud and corruption charges against Jacob Zuma, effectively putting the ANC's leader and presidential candidate back in the dock.

"It is very ominous. It is possible that they are doing this to pave the way for Mr Zuma not to be prosecuted," Van der Merwe said.

The ad hoc committee said it would table its final report on Pikoli's dismissal on January 29.

The National Assembly is expected to vote on the matter on January 30, and the National Council of Provinces to follow suit on February 3.