National Director of Public Prosecutions Shaun Abrahams is fighting an urgent court bid to block him from deciding whether former President Jacob Zuma will finally go on trial.

The Council for the Advancement of the South African Constitution (CASAC) is seeking an urgent Constitutional Court order that will interdict Abrahams from making a decision on Zuma's fate on the basis that the highest court in the land is currently deciding whether the NDPP's appointment is valid.

CASAC also argues that Abrahams is perceived to not be independent and is not the right person to make the history-making call on Zuma.

But Abrahams has hit back in court papers filed on Friday.

"CASAC fail to appreciate that‚ given the highly charged nature of the matter‚ there is of course a risk that there will be a perception of bias irrespective of who it is that ultimately makes the decision.

"If‚ for example‚ President Ramaphosa appoints a new NDPP‚ who decides to proceed with the charges‚ a significant sector of the public will doubtless suspect that the new President has designated my successor with a view to settling political scores or to pander to the public perception to which CASAC refers.

"Conversely‚ should a NDPP appointed by the new president determine not to proceed‚ this will doubtless be perceived as an effort to avoid triggering dissent within the ranks of the ruling party."

Abrahams said he views the urgent application to block his Zuma decision as a "serious threat" to the independence of the National Prosecuting Authority.

"I must emphasise that I stand ready and willing to announce my decision. I take strong exception to any suggestion that I lack the requisite independence‚" he said in court papers. Abrahams has indicated that he could make an announcement on the Zuma case on or after March 15. He had agreed to give CASAC two weeks notice of his intention to announce his decision‚ and therefore has to wait until mid-March to tell both Zuma and the public what he has already decided.

Abrahams said he was surprised that CASAC did not allow him to make the announcement sooner.

"It is manifestly in the public interest that the decision be announced as soon as possible."

He argues that it would be "inconsistent with the principles of equality before the law‚ separation of powers‚ and prosecutorial independence‚ for a court to interdict a prosecutorial decision selectively‚ with respect to a single individual".

According to Abrahams‚ there is no "substantive obstacle to me making a decision about Mr Zuma's prosecution"‚ as the High Court that found his appointment was invalid had not found that he was not independent.

He says "no irreparable harm" will flow from him announcing his Zuma decision - as CASAC can seek to review it in court‚ if it's dissatisfied.