The MP who forced the investigation into Countdown supermarkets has dismissed a Government push for the supermarket industry to adopt a voluntary code of conduct.
The Labour Party's Shane Jones says the idea is a joke and a tougher regime is needed to police the conduct of the country's two big supermarket chains.
Commerce Minister Craig Foss has already met representatives of Progressive Enterprises, which runs the Countdown chain, and will meet executives from Foodstuffs next week.
Mr Foss says he wants to help the industry adopt a voluntary code of conduct but Mr Jones says the corporate culture in the industry will not change until an approach is adopted that involves less carrot and more stick.
The Commerce Commission is investigating Countdown after Mr Jones accused the chain of engaging in uncompetitive conduct.
Both the Labour and Green parties oppose a voluntary code, saying it needs to be compulsory.