The National Assembly on Tuesday adopted a revised code of ethics for MPs which prohibits all elected public representatives from doing business with the state.

The Code of Ethical Conduct and Disclosure of Member's Interests will take effect on November 1.

The office of African National Congress Chief Whip Stone Sizani said the ruling party proposed this date to give those who were affected time to comply with the new code.

"It is important that members and public representatives are thoroughly workshopped on the provisions to ensure that on the effective date they are compliant."

Under the code, the ban on doing business with government extends to the spouses and dependants of elected representatives.

It also prohibits the business partners of members of Cabinet, Parliament and provincial legislatures from benefiting from state contracts "arising out of the association with the member".

The code was adopted by the National Council of Provinces in March.

It was passed by the National Assembly in the wake of a Sunday press report that 19 members of President Jacob Zuma's Cabinet, including the president himself, hold private business interests, according to the Companies and Intellectual Property Commission.

City Press reported that Deputy Minister of Agriculture, Forestry and Fisheries Bheki Cele owns a company called Ithembelihle with a business partner Lawrence Mazibuko, who in turns directs a security company employed by a number of government clients, including the South African Revenue Service.

Sizani earlier this week said the revised code would get rid of the anomaly that members of Cabinet were reported to be doing business with the state "whilst making laws forbidding civil servants from doing the same".