The Cook Islands High Court is set to hear an application which aims to stop the government from allowing more purse seiners fishing in its waters.
About 4,000 people have signed a petition against the government's latest deal with the European Union, which would allow four Spanish vessels to fish in Cook Islands waters for at least eight years.
The draft agreement allows for the netting of tuna, an annual quota of 7,000 tonnes to be exceeded and six months of experimental fishing a year.
A Rarotonga businessman, William Framhein, has lodged an application to the High Court for a judicial review of the deal.
"We are seeking relief to have these draft documents quashed, or any documents associated with the draft agreement and protocol between the Cook Islands government and the European Union. In excess of 4,000 people have signed the petition and there is also an absence of customary law."
William Framhein says the application is listed to be heard next Friday, but the government has a right of reply which could mean the hearing is pushed back.