A maritime lawyer says attempts are being made by two large fishing companies to water down rules surrounding the reflagging of foreign charter fishing vessels.
The Foreign Charter Vessels and Other Matters Bill is being debated at a Primary Production Committee meeting.
Peter Dawson told MPs on Monday that Sealord and Sanford have suggested an alternative where a vessel is deemed a New Zealand ship but will still fly its own flag.
Mr Dawson said this system is used in Australia and would be a backward step in protecting foreign crews from labour abuse.
He said the system would mean neither the Minimum Wage Act nor the Wages Protection Act would apply to the vessels.
Under the bill, reflagging will be compulsory in New Zealand from 2016.