The Australian government will send a plane to the Southern Ocean to monitor the Japanese whale hunt from early next year.
The government said an A319 plane would be sent during the whaling season which begins in January and ends in March, in an effort to step up its monitoring of the fleets.
Environment Minister Greg Hunt said it was important Australia has a monitoring presence in the area, given the risk of confrontation between whalers and anti-whaling protesters, in order to ensure both parties obey the law.
Sea Shepherd campaigners set off for Antarctic waters on Wednesday. Jeff Hansen, a spokesperson for the anti-whaling group, said a plane would not be able to adequately monitor what is happening on the water.
"This sending planes overhead is a really pathetic response and it's really a waste of taxpayers' dollars. Sea Shepherd is already doing that job."
Opposition parties are accusing the Government of breaking a promise made in the lead-up to the election to send a Customs vessel to the area.
Under Australian law, such a vessel would have to turn around any Japanese ship that conducted illegal whaling.
Greens Senator Peter Wish-Wilson said sending a plane will have a limited impact, and the Government has a boat ready-made for such a mission.
Last year the hunt in the Southern Ocean netted just 103 minke whales, less than half the tally the previous year, and no fin whales. Japanese authorities blamed "unforgivable sabotage" by activists.