Rock star Sting has used his latest visit to Brazil to urge the government there to listen to the concerns of indigenous peoples over a proposed new hydro-electric dam in the Amazon.
He was speaking at a press conference in Sao Paulo where he was reunited with indigenous leader Raoni Metyktire who joined him in a similar campaign 20 years ago which attracted worldwide attention.
Indigenous tribes in the Amazon say the Belo Monte project, which would be the third largest hydro-electric dam in the world, poses a threat to their way of life.
Sting said Brazil was in the front line of the fight against climate change and it was even more important now to listen to the voices of those who live there than it had been 20 years ago.
In the earlier campaign, Sting and Chief Raoni toured many parts of the world in opposition to a hydro-electric project on the Xingu River in the Amazon.
It proved to be an attention-grabbing combination of a rock star standing alongside the striking figure of an indigenous leader whose lower lip is expanded several centimetres by a traditional plate, a trademark of his tribe.
With renewed international attention on the cause of protecting the Amazon, the original hydro-electric project was abandoned, but now the Brazilian government is proposing a new scheme which they say is more environmentally friendly.
Critics have insisted the Belo Monte dam would still flood large areas of rainforest, have a major impact on fish stocks and undermine the way of life of thousands of indigenous people.
Speaking to the BBC, Sting said while the decision was for Brazilians alone, the debate had an impact far beyond South America's largest country.
"This is the heart of the Amazon and what happens here affects the whole world," he said.
"This was my intuition but now the science is backing that up, I mean substantial science is saying this is true.
"We need to save this forest.
"It is the biggest contribution to greenhouse gases - deforestation. Way beyond industrial pollution, way beyond the burning of fossil fuel for transport, or heating."
He pointed to the way the recent financial crisis had been handled and suggested the same approach was needed for the environment.
"It is too big and important to fail, because without the environment there are no economics," he said.
"...Brazil needs to say, OK, here's how we solve this problem - here's how we continue to develop but do not destroy the asset. The asset is incredibly important.
"We are looking to Brazil for leadership here."
He said it was crucial to have full consultation on Belo Monte.
"I can't pretend to be an expert on hydro-electric power - that is ridiculous. At the same time I want all the arguments for and against to be heard.
"This is my only concern - then it is up to the Brazilian people."
Indigenous leaders are bitter because they believe the consultations held so far have been inadequate and that their voices are not being heard.
The authorities say the area to be flooded is much less than previously planned and that steps can be taken to protect indigenous territories.
'Very high price'
But when asked about these claims Chief Raoni said this had not been made clear to his people.
"The authorities never called a meeting with us, with our leaders to explain this, to have a consultation over Belo Monte," he said.
"If they had done this we would have understood things better. This is what I think is bad."
Andrea Leme da Silva, co-ordinator of the Indigenous and Traditional People's Programme of Conservation International said the consultation had been inadequate.
"Traditional local people - indigenous and riverside dwellers are not aware of the real impact, and have been informed of the impact of the dam," she said.
"I think we will pay a very high environmental and social price."
The Xingu basin is a place of very high biodiversity and, according to specialists, the same biodiversity of fish as the whole of Europe.
"From the social side the Xingu is an indigenous river," Ms da Silva added. "You have 24 different ethnic groups that are living there.
"These groups have their ancestors and history and the government has not considered this."
A decision on an environmental approval for the Belo Monte dam is said to be imminent, but the debate surrounding this proposal seems as contentious now as it was two decades ago.