The validity of the parliamentary code of conduct for MPs was called into question in the Specialised Commercial Crimes Court in Pretoria yesterday.

Lawyers representing former African National Congress (ANC) chief whip Tony Yengeni said the code was never approved.

Hilton Epstein, Yengeni's advocate, had been approved instead.

Lawyers for Yengeni and his co-accused, Michael Woerfel, the SA MD of European Aeronautic Defence and Space Company (EADS), launched an objection to the charge sheet produced by the state, claiming that nowhere did it show that an offence had been committed.

Yengeni and Woerfel face fraud charges relating to the government's R43bn arms programme.

The objection was argued before the hearing of the two men could begin.

State prosecutor Jan Henning said the code of conduct had been approved, and that it was "a matter for evidence".

Epstein then indicated that his team would abandon the challenge should the prosecution produce such evidence.

Such a challenge is unexpected, and if the allegation is true it would also raise a number of questions because Yengeni has for some time been a senior member of the party and, the prosecution claims, had complied in "some respects" with its provisions.

Woerfel, whose group won contracts in the arms deal, arranged a big discount on a Mercedes-Benz for Yengeni when he was chairman of Parliament's standing committee on defence.

Legal representatives lodged the objection to the charge sheet in court yesterday, arguing that the state relied too heavily on an inferential process without objective facts to back this up.

Mike Hellens, Woerfel's advocate, said in reference to the state's case: "What this amounts to is to say we don't have direct evidence'".

The objection means the court will have to make a ruling on whether the case will go to trial or not.

Yengeni's lawyers have cited section 58 of the constitution, which deals with parliamentary privilege.

The section protects parliamentarians from civil and criminal charges, and imprisonment for anything they have said or submitted to Parliament or its committees.

Henning said it was "in law immaterial whether any act has been committed" by the two.

"It is, after all, the integrity of the office that the (Corruption) Act seeks to protect."

He said: "To elicit or solicit a bribe strikes at the heart of public office. It violates the public's trust the act which is forbidden, is the unlawful giving or receipt or a benefit, not the subsequent act."

Henning said an element of the state's case was that only one inference could be made from the discount Yengeni received on the Mercedes-Benz.

He said: "We say the only inference is that the (benefit) was given with a corrupt intent."

With acknowledgements to Bonile Ngqiyaza and Business Day.