In a rare political consensus, Labour, the Greens and ACT are all backing the Government's condemnation of South Korea's decision to resume whaling.
South Korea is copying Japan's controversial "scientific research" hunting expeditions, using a loophole in the international moratorium.
South Korea says the planned hunt comes in response to calls from commercial fishers concerned that whales are depleting fish stocks.
Foreign Affairs Minister Murray McCully slammed the proposition on Thursday as a serious setback to whale conservation.
"The portrayal of this initiative as a `scientific programme' will have no more credibility than the so-called scientific programme conducted by Japan, which has long been recognised as commercial whaling in drag," he said.
He plans to raise his concerns with South Korea's foreign minister at an East Asia Summit in Cambodia next week, while New Zealand's ambassador in Seoul was instructed to immediately register "serious concerns" with the South Korean government.
Greens co-leader Metiria Turei says her party is outraged at Korea's proposition, and disappointed that the International Whaling Commission hasn't closed the scientific purposes loophole.
"The continued slaughter of whales is unacceptable and our Government should do everything it can to help end this abhorrent practice," she said.
Labour's conservation spokeswoman Ruth Dyson welcomed Mr McCully's strong and prompt stance on the issue.
"The global community has no taste for whale slaughter. And let's not pussy-foot around - that is what this is," she said.
ACT leader John Banks says it's an "international outrage".
"Like Japan, it remains ludicrous that they believe you need to kill whales to save them," he said.
"This thinking is as lamentable as it is obscene."
Prime Minister John Key, who is in Sydney, joined Australia in condemning South Korea's plan to resume whaling on Thursday.
"It's a terrible step in the wrong direction. We think it's unnecessary, we think it's inappropriate and we don't think the stocks would support that," Mr Key told reporters.
"Most people around the world would be disappointed if the Koreans took this step."
Greenpeace is also condemning the plans.
“We’ve got no place in the 21st century for an international body that’s still arguing over where and how whales can be killed,” Greenpeace ocean campaigner Karli Thomas says.
“They are under threat from so many different sources. Around 300,000 whales and dolphins are estimated to die every year entangled in fishing gear.”
NZN / RadioLIVE