The High Court in Auckland will start hearing a case on Tuesday challenging the kiwifruit industry's single desk marketing structure and the way it's being run.
Turners & Growers is claiming that regulations giving the Zespri monopoly control over most kiwifruit export markets are unlawful.
The fresh produce company also claims Zespri has abused its dominant position in a number of ways, including seeking to tie growers, suppliers and post-harvest operators into exclusivity contracts.
The High Court will consider whether the export regulations are unlawful and if it has jurisdiction to decide whether Zespri has been acting in breach of other regulations.
Remaining issues raised by Turners & Growers will be heard early next year.