Wellington  - Shipmates on two Navy frigates sent by the New Zealand government to France's atmospheric nuclear testing site in the South Pacific - possibly the first state-sponsored Ban the Bomb protest - gathered Friday for a 35th anniversary reunion.

The 1973 operation was a defining moment in New Zealand's history and forerunner of the country's anti-nuclear policy, which was enshrined in law 14 years later, provoking an angry United States to formally renounce Wellington's ally status.

In the words of one former legislator, the anti-nuclear stance is "deeply embedded in the psyche of all New Zealanders - it is an integral part of New Zealand's sense of identity."

That is why the ageing veterans of the frigate HMNZS Otago and the HMNZS Canterbury, which replaced it off the French testing site at Mururoa Atoll after 35 days at sea, are holding their reunion this weekend at the port city of Napier.

Gerry Wright, who was operations officer on the Otago, during the reunion will launch a book, Mururoa Protest, which he has written and published to ensure the exercise's lasting place in history.

France and China were still conducting nuclear tests in the atmosphere in 1973, while the United States and Soviet Union maintained underground testing programmes. New Zealand's Prime Minister of the day, Norman Kirk, was incensed that the French, who had moved the tests to the Pacific in 1966 after losing their former site in the Sahara when Algeria gained independence, were polluting a faraway ocean in what he saw as New Zealand's backyard.

When the French rejected an International Court of Justice ruling banning a new series of tests, Kirk ordered the Navy to prepare a ship for sea - not with any thought of physically stopping the tests, but to be "a silent accusing witness with the power to bring alive the conscience of the world."

Determined to "ensure the eyes of the world are riveted on Mururoa," Kirk put cabinet minister Fraser Colman, father of three young daughters, on board the Otago, which sailed in June from Auckland with 245 aboard, and directed the Navy to take along two newsmen - one of them this correspondent - and a TV cameraman.

It was a state-sponsored anti-nuclear publicity campaign without parallel and a piece of daring diplomacy that defied advice from his own officials and New Zealand's closest allies. And it worked, putting the operation on front pages and radio and TV stations around the world.

The French had never announced their tests or even confirmed them after they had been identified by seismologists, but when they set off a nuclear explosion - estimated at 15-kilotons by the US Atomic Energy Detection System - on July 21 from a balloon above Mururoa, it went around the world in minutes, followed by photographs of the tell-tale mushroom cloud.

"Never before has world opinion on nuclear testing been so stirred," Kirk said after receiving a mass of supportive messages.

Defiantly, the French set off three more explosions before year's end and seven more in the atmosphere in 1974, before going underground with 124 tests between 1975 and 1991.

After a four-year moratorium, France resumed testing to renewed criticism from New Zealand, Australia and other countries in 1995, detonating six more before the last and biggest at 120 kilotons on January 7, 1996.

Fraser Colman, who transferred from the Otago, which sailed home after an unprecedented 35 days at sea, to the replacement ship, will miss the reunion by a few weeks. He died last month, aged 83. (dpa)