Wellington is seeking a ruling by the International Court of Justice in The Hague, the judicial arm of the UN, against the planned tests in French Polynesia. The New Zealand case will argue that France's undertaking to conduct an environmental impact study after the tests is meaningless, and such a study should be independently carried out before the tests so as to gauge their impact on marine life from possible radiation leaks and on the coral atolls at Mururoa from the impact of underground explosions.
Australia, which had earlier ruled out such action, swung behind the court challenge and said it would support New Zealand. But both sides have to agree that a dispute should be referred to the International Court, and since 1974 France has declined to accept the jurisdiction of the court in any field. Yesterday Paris made it clear that its policy remained unchanged.
This impasse leaves New Zealand trying to reopen a case referred in 1973, before France withdrew recognition of the court. Australia took a separate action against France the same year.
Both countries were then reflecting growing alarm among their smaller Pacific island neighbours over the atmospheric tests which France had transferred to Mururoa from its original testing ground in Algeria, following Algerian independence in 1960. France continued testing in the atmosphere up to 1974, ignoring a treaty under which the US, the Soviet Union and Britain had transferred their nuclear tests underground in 1963.
Even as the International Court actions proceeded during 1973 and 1974, France conducted several series of atmospheric tests at Mururoa. In September 1974 it announced that it had "reached a stage in our nuclear technology that makes it possible for us to continue our programme by underground testing".
The International Court suspended judgment on Australia's case, which had specifically devolved on atmospheric tests. Gough Whitlam, then Prime Minister, claimed a partial victory by asserting that France had been forced to put its tests underground.
Gareth Evans, Australia's Foreign Minister, said yesterday that Canberra had resisted reopening its 1973 action during the furore over the latest proposed tests because the Government had received legal advice that there was little chance of success. However, it would intervene to support New Zealand's revival of its case, which was more broadly drafted against contamination from nuclear testing in general.