Negotiations over the future of international whaling are delicately poised and a compromise between pro- and anti-whaling nations is the only realistic goal to push for, the Government says.

Environmentalists and Opposition parties are pushing for New Zealand to take the stance with the International Whaling Commission (IWC) of eliminating whaling in the southern ocean.

New Zealand needs to get enough support for its yet to be finalised compromise by April 22 so it can then be taken to an IWC annual meeting in Morocco in June for a vote.

At a media conference headed by Foreign Minister Murray McCully and New Zealand's IWC representative Sir Geoffrey Palmer yesterday, the pair said New Zealanders needed to put emotion aside and accept that different countries and cultures had different takes on whaling.

Mr McCully said the "acceptable" part of any compromise it was yet to be agreed to, but it would have to involve a big reduction in the annual whale cull, and that was the mandate the Government had given to New Zealand's negotiating team.

Sir Geoffrey said the IWC had been fraught with difficulties and opposing views for many years, and the latest negotiations had been intense for the past two years.

Japan carries out whaling in the southern ocean by making use of an IWC clause which allows governments to skirt an international moratorium by allowing for "scientific" whaling. The clause allows for whale meat to be disposed of in any way, including selling it commercially.

Australia is taking a tougher stance than New Zealand and wants to challenge Japan's "scientific" whaling through an international court process, but Sir Geoffrey said today he believed Japan would have a strong case.

He also said if the current negotiations failed there was a risk the IWC could collapse, meaning any control on international whaling would be lost.

"There is a big risk of that and I don't relish it," he said.

The Labour Party's foreign affairs spokesman Chris Carter was critical of the Government for having in effect "laid its cards on the table" for pro-whaling nations to see.

He said he wasn't convinced the collapse of the IWC would be dire, as the support Japan had from IWC members was only from countries duty-bound to return support which they received from Japan in other diplomatic areas, rather than because of their own whaling beliefs.

With Iceland having applied to join the European Union and potentially having to drop its whaling activities as a result, it meant Norway, which currently hunts whales in objection to the IWC whaling moratorium, and Japan, could be left as the only active whaling countries, Mr Carter said.

That would leave them in a state of growing isolation and exposure on the international stage.

Mr Carter said if anti-whaling countries took Japan to court, it would also be embarrassing and damaging for the Japanese.

"It could well be the scenario which I guess the Australians are hoping for -- that the Japanese could dump the case."

Mr Carter said while any reduction in whale killings would be a good result, the unintended consequences could be that other countries could use it as a precedent and put their hands up to get involved in commercial whaling.

Any compromise would also be damaging to New Zealand's international reputation as a "pure and environmentally responsible world citizen".

That brand was already coming under international scrutiny, Mr Carter said.