Deputy President Jacob Zuma launched a furious attack last night on the Scorpions' investigation into whether he solicited a bribe in connection with the arms deal, signalling a desperate fightback by the veteran politician to rescue his career.

Breaking with the pattern of denials that have characterised his previous utterances on the allegations dogging him, Zuma lashed out at the Scorpions. He called the leaking at the weekend of the Scorpions' questions to him on the arms deal "totally unacceptable and despicable".

As the controversy around Zuma intensified, President Thabo Mbeki indicated he was not contemplating immediate action against his deputy.

Presidential spokesperson Bheki Khumalo said on inquiry yesterday that Mbeki had previously indicated that no action would be taken until a charge had been laid. "That position still stands," Khumalo said.

The Scorpions' decision to ask Zuma a wide-ranging set of questions comes as the unit attempts to conclude its long-standing investigations into the arms deal amid increasing political tension.

The tension has been heightened by an anonymous smear campaign against Bulelani Ngcuka, head of the National Prosecuting Authority, under whose authority the Scorpions fall.

The Scorpions' decision to press ahead with the investigation suggests Zuma's political prospects could be severely damaged, especially in the run-up to elections next year.

Zuma said last night: "I find it totally unacceptable and despicable that questions that they sent to me have appeared in a Sunday newspaper. This is a serious breach of confidentiality and is contrary to the spirit and terms of the National Prosecuting Authority Act, relating to the confidentiality of information received and disseminated.

"For more than three years, I have chosen to maintain my silence as I felt that would allow the investigators space to continue with the probe unhindered.

"Public statements from my side would have easily been misconstrued to be interfering with the investigation or seeking to influence it in one way or the other."

Zuma said he now had "a serious problem" with the manner in which the directorate was conducting the investigation. He did not indicate whether he intended to continue to co-operate.

The questions follow the publication of court documents which include an encrypted fax sent by Alain Thetard, the local head of a French arms contractor, Thales, which states that Zuma solicited a bribe in exchange for political support in connection with the arms deal.

The questions focus on Zuma's relationship with one of the major contractors in SA's R50bn arms deal, Schabir Shaik, whose brother Chippy was the head of the procurement team.

Opposition parties differed on Zuma's next move, with the Democratic Alliance saying he should step down, while the Independent Democrats' Patricia de Lille said it was up to Mbeki.

With acknowledgements to Tim Cohen and the Business Day.