The Labour Party has launched a petition against allowing commercial whaling to restart.
A meeting of International Whaling Commission (IWC) nations in the United States last weekend had tried but failed to reach a compromise.
Reports said under consideration was an idea to allow Japan, Norway and Iceland to openly hunt whales despite a 1986 moratorium on commercial whaling, but aim to reduce the total catch over the next 10 years.
The compromise would close a scientific whaling loophole that Japan uses to catch hundreds of whales every year.
Australia made it clear it would not support such a move but New Zealand backs reaching a diplomatic solution if it can achieve a dramatic reduction in the number of whales killed.
Labour's Chris Carter today put up a petition on his website asking people to tick yes to the statement "I oppose all moves to restart commercial whaling".
Mr Carter said the public needed to put pressure on the Government and send a clear message that resumption of commercial whaling was not an option.
"(Prime Minister) John Key's great plan to save the whales is apparently allowing the Japanese to hunt them commercially. This appalling move can only be stopped by public pressure, so the New Zealand Labour Party is starting an online petition," Mr Carter said.
Agreeing to commercial whaling would harm New Zealand's reputation and the Government should join Australia if it decides to take a case to the International Court of Justice. Australia has promised to do that this year if diplomatic efforts fail.
Mr Key previously said the Government would consider backing the court action if no progress was made.
New Zealand's IWC representative, Sir Geoffrey Palmer, a former Labour prime minister, said it would be "enormous progress" if Japan was stopped from using the scientific whaling loophole.
Foreign Minister Murray McCully declined to comment on the petition.
