Diplomatic cables obtained by WikiLeaks show Australia was willing to compromise as late as February, as long as the deal greatly lowered the hunt and excluded waters near Antarctica, The Age newspaper of Melbourne reported Monday.
The government is under pressure to send its new Southern Ocean patrol ship to observe an impending clash between the anti-whaling group Sea Shepherd and the Japanese fleet off the Antarctic coast.
On Monday, both sides were sailing along the pack ice edge.
The cables also show that Peter Garrett, then environment minister, warned the U.S. ambassador Feb. 5 that the Labor government was constrained by the Greens' moves in Parliament to investigate Japanese "spy flights" over anti-whaling ships.
Two weeks later Prime Minister Kevin Rudd, who has since left office, went on television to say the hunt must end and pledged Australia would take Japan to the International Court of Justice, which it has.
Australia's dispute with Japan has intensified in the last year.