The Government is making a fresh attempt at getting Antarctica's Ross Sea protected.
The annual meeting of the Commission for the Conservation of Antarctic Marine Living Resources is under way in Tasmania where officials will, for the third time, try to create the world's largest marine protected area.
It would protect 1.32 million square kilometres of ocean.
The original proposal has been cut dramatically from the meeting in 2012, and the most recent one in July this year at which New Zealand and the United States had pitched protecting double that amount of ocean.
Foreign Minister Murray McCully says a bone of contention now is a clause that would mean the protection would only last a certain number of years. Mr McCully says most things are negotiable.
A vote is expected next week.