Ekapoj Yodpinit, president of the Shrimp Farmers' Club in Surat Thani province, said: "We condemn the newly introduced measures as not necessary and impractical. They have been introduced to limit our exports."

He said that although only Queensland had introduced the measures, they were likely to be applied in other states soon.

Ekapoj said he, along with shrimp farmers' representatives from provinces including Krabi, Pattani, Trang, Ranong, Satun and Chantaburi, yesterday submitted a letter of complaint to the Australian Embassy.

On Monday, Queensland introduced a regulation requiring exporters to boil prawns for a certain period to a certain temperature. "The heating requirement will make it impossible for prawns to maintain their quality," Ekapoj said.

Australian authorities said they required imported shrimp to comply with quarantine conditions to manage yellow-head virus, white-spot syndrome virus and taura syndrome. They proposed stronger risk-management requiring: country or zone disease freedom; or removal of the head and shell and testing for possible viruses; or a high level of processing for uncooked prawns, including crumbed prawns, pastries or dim sum-type products; or cooking products offshore with acceptable certification or cooking onshore under quarantine control.

Ekapoj said the measures would damage Thai shrimp exports because they were not practical.

He cited recent restrictive measures against chicken exports which effectively blocked the Thai chicken industry's access to Australia. Authorities required exporters to boil chicken at 74C for 165 minutes or 80C for 125 minutes. After meeting the requirements, the chicken had decomposed to the point where it was not sellable. Thailand exported 10,421 tonnes of prawns worth Bt2.4 billion to Australia last year. In the first 10 months of this year, Thailand exported 16,233 tonnes worth Bt1.883 billion.

Ekapoj said exports could continue to rise if Australia ends protective trade measures.