About 100 former New Zealand nuclear test site workers are expected to take legal action against the United Kingdom government following a British high court ruling.
The ruling allows ex-servicemen who took part in the tests off Australia and Christmas Island in the 1950s to sue the British government for compensation.
The ruling issued by Judge David Foskett on Friday means the British government could face its largest class action yet.
About 550 New Zealand servicemen took part in the atomic tests and the Nuclear Test Veterans Association says 150 are still alive.
Chair Roy Sefton says about 100 New Zealand veterans or their widows will now sue the British government for compensation.
He says they are seeking recognition and compensation for radiation-linked illnesses, including cancer.
Mr Sefton says the ruling is the first step, of possibly another three years of legal battles.
But he hopes the British government will speed the process up before more veterans and widows die.