The leader of an Amazonian tribe pleaded for help yesterday in protecting the forest that has been his people's home for generations. He urged Britain to fight mining interests and warned environmentally conscious consumers in the West against the fashionable practice of buying up tracts of land from thousands of miles away.

Speaking in St Ethelburga's church in the City of London, a centre for reconciliation after being destroyed by an IRA bomb in 1993, Davi Kopenawa Yanomami said he believes the threat posed to his homeland by industrialisation is greater than ever. He added that he will stop at nothing to get home his message to Western consumers, green campaigners and politicians.

Dressed in a traditional costume of black, red and yellow headdress, with red facepaint and green feathers, the shaman and winner of the UN Global 500 award, for his conservation efforts, had a direct message for Gordon Brown. He said that, if the Prime Minister is serious on the environment, he cannot afford to ignore the needs of indigenous people living on the frontline of environmental damage. "This Prime Minister who is important and at the top," he said, "he has to give support to indigenous people who want to live forever and live in peace. I urge Mr Brown to look to the sun, the sky, the rivers and the forest, because the forest is our life. Without the forest everyone will be ill, whites as well as indigenous people."

The population of the Yanomami tribe, whose land spans Brazil and Venezuela, is currently around 27,000. But the threat of the modern world is palpable. In the 1980s, the effects of gold mining ravaged their health and destroyed their villages, killing 20 per cent of the tribe in seven years. After years of campaigning, a Yanomami reserve was created, offering them some protection from industrialisation. However, although the Yanomami have leave to remain, they have never been given official rights to the land.

And now a new surge of mining interest is putting them under renewed threat. The Brazilian government is pushing for the reserve to be reduced and opened up to mining. Survival International estimates that already up to 1,000 goldminers are operating illegally within Yanomami territory.

"I want you people here who live far away to help us," explained the tribe's unofficial roving envoy. "I don't want you to send money. I want you to put pressure on the Brazilian government. They have drawn up a project that will involve mining in indigenous territories. This will be very dangerous for us because it brings heavy machinery, which pollutes the rivers and the streams. When the miners leave, the pollution remains."

But Davi Yanomami was also quick to criticise fashionable land-buying schemes. These have become as de rigueur for green consumers in Britain as organic food or carbon-footprint reduction. They have even caught the eye of the Prime Minister, who has enlisted a former Tory donor, Johan Eliasch, as a consultant to the Government on deforestation. Mr Eliasch co-founded Cool Earth, an organisation which encourages people to sponsor areas of the rainforest as a means of protecting it. He has proved effective at garnering support in the UK and US.

A spokesperson for Cool Earth said that their purchase of forests, which they then "return" to local communities, comes with "no strings attached, aside from that they keep it standing".

Yet the tribes who have lived in the forest for generations have a message that does not make pleasant listening for environmental investors. "Buying up our forest makes me very sad," said Davi Yanomami. "There is no money in the whole world that will buy the Amazon forest. You can't buy land like you can buy meat or clothes. Land will always remain. We can use and use the earth and it will always be there. But money you can throw away in a river – it won't last.

"I'm very worried because people from England come to Brazil and think it's a nice forest, and want to protect it, so they buy and buy. But one day they will sell. When white people buy, they always sell, and we wouldn't believe their promises to the contrary."

A report launched yesterday by Survival International has outlined how buying land could be far more damaging than leaving it to the tribesmen who have lived there for centuries. They argue that, by selling land, the serious issue of granting permanent land rights for indigenous people is bypassed. The report, Progress Can Kill, suggests that indigenous land ownership is the key to solving the environmental future, and the future of tribes across the world. Survival International blamed the separation of tribespeople from their land on their increased rates of Western illness, suicide and mental health problems.

According to the director of Survival International, Stephen Corry, schemes that allow people to buy chunks of forest "divert attention" from the serious issue of getting land rights for indigenous people. "The key is land. If these people own their land and control their land it's very likely to break this cycle. For some reason people think it's romantic to assert the rights of these people," said Mr Corry. "But it's not romance; it's science. If you look at satellite photography you can see that the land lived in by indigenous people does not get logged. Survival has a problem with the claims that organisations like Cool Earth are making, because they divert attention from the real way to save the Amazonian rainforest, which is to leave it in its people's hands."

Hylton Murray-Philipson, head of Rainforest Concern, agreed that schemes offering people the chance to buy sections of forest were misleading. "Only 10 per cent of the Brazilian Amazon is even theoretically available for private purchase. The rest is government owned or protected. So, even if you bought up that whole 10 per cent, you wouldn't solve the problem; the real problem is the illegal invasion of protected land," he said. "Ensuring that indigenous people are protected on the land is the best way of conserving the rainforest. Anything else is all about money. There's hardly a square inch of protected land that doesn't need to be fought over, but turning up with a cheque book is not going to work."

Survivors from a lost world
Population: About 27,000
Territory: Yanomami land, straddling northern Brazil and southern Venezuela. In Brazil the tribe occupies 24 million acres of rainforest, a region four times the size of Switzerland.

History: In the 1980s, goldminers invaded Yanomami villages, shooting tribespeople and spreading diseases that they had not developed immunity to. This reduced the Yanomami population by 20 per cent in just seven years.

Culture: The tribe lives in communal houses, called yanos or shabonos, which can hold up to 400 people. The yanos are built in a large ring with an open space for ceremonies in the centre. Each family has its own hearth, with hammocks arranged around a fire.

Survival: The Yanomami are hunter-gatherers, using bows and arrows tipped with poison. They have an in-depth understanding of their land, and use more than 500 different species of plants in their food, medicine and house building.

(By Emily Dugan, The Independent, 17/10/ 2007)