THE Kakadu national park, with its lush forests, rocky waterholes and abundance of wildlife, is familiar to cinema- goers as the stunning natural backdrop to the Crocodile Dundee films. This remote area of Australia's Northern Territory is now the scene of a far more compelling real-life drama. It centres on Yvonne Margarula, an Aboriginal woman leading a fight by the last 27 remaining members of her tribe to prevent a British multinational from opening a uranium mine in the heart of their tribal land.

The Mirrar tribe has the title to 5% of Kakadu, which is notable not only for its natural beauty as a United Nations World Heritage Site, but also for the fact that it contains some of the largest deposits of uranium on Earth.

Since the 1970s, ore has been extracted by Energy Resources of Australia (ERA) from the Ranger mine, which lies on the Mirrar land. Then, in 1982, Margarula's father, Toby Gangale, the tribe's then spiritual leader, signed a lease allowing the company to start work at a second mine at Jabiluka - believed to be capable of yielding uranium worth £40m a year for 28 years.

Last November, a large stake in Jabiluka was acquired by Britain's Rio Tinto, one of the world's two mining giants, when it bought a controlling interest in ERA. The mine is ready to start operating.

Mirrar tribesmen have long claimed the 1982 agreement was signed under duress. Their position has been strengthened by the proposal by ERA to build a road from Jabiluka across their territory, for which the assent of the Mirrar and other tribes nearby is required.

Under the plan, the uranium ore would be trucked from Jabiluka to Ranger, where there is a processing plant. The uranium oxide produced would be sold on to clients such as British Energy and other European and American utilities.

Margarula, hoping to preserve the spirit of her late father as much as save her people's ancient land, has said the supply must stop. Her campaign will come to a head next month, when Rio Tinto is expected to make a final appeal to the Mirrar and several other tribes in the vicinity. The offer will include the injection of about £300m into infrastructure, health and employment opportunities over the mine's 20-year life. So persuasive has been the new offer that all the other tribes in the Kakadu region have agreed to accept it.

The Mirrar are still holding out. Margarula insists her people's survival depends on an end to western influence, which she says has helped decimate their numbers through alcoholism and disease. With the help of the Gundjehmi Aboriginal Corporation Association, the Mirrar are spreading their message worldwide through a campaign website accusing Rio Tinto of "genocidal" activities.

Supporters plan protests outside the company's head office in London. A spokesman for ERA defended plans for Jabiluka last week, saying the World Heritage Committee believed it would have negligible impact on Kakadu. "Since 1980 we have given A$64m (£20m) to the aboriginal people in this region," he noted. Faced with such entrenched resistance, Rio Tinto has nevertheless brought forward plans to sell its Australian uranium. The potential buyers include the French nuclear utility Cogema. The Mirrar's campaign has met scepticism, however, even among some sympathetic to their plight. Bob Collins, a former Labor senator now in charge of implementing an indigenous development programme, said the underground mine built at Jabiluka was "clearly more benign" than the vast open-cast mine originally planned in 1982. The ore transport road would obviate the need for an ugly processing plant at Jabiluka itself. Margarula is having none of it. Under Australia's new land rights laws, she is Jabiluka's landlord and Rio Tinto is her tenant. And now she is seeking an eviction order.