Giant mapajo trees rise imposingly above the canopy, the howls of monkeys reverberate in the distance, and rare jaguars roam unconcealed in the undergrowth: the Bolivian jungle is a place of unspoilt natural beauty. Rated eighth in the world for its biodiversity, more than half of Bolivia is still covered by pristine forests. But what for some is picturesque remoteness, is for others the curse of underdevelopment.

The Isiboro Sécure Indigenous Territory and National Park (TIPNIS) is no exception. It's home to thousands of species of birds, mammals and plants. But it's also one of the poorest areas in Latin America.

With its 2.5m acres, the TIPNIS (from its initials in Spanish) is doubly protected, as a park and as the territory of the Moxeños, Yurakarés and Chimanes indigenous people, to whom the government seems in a rush to want to bring its controversial version of progress and prosperity.

"Whether they like it or not, we will build that road," President Evo Morales insisted last week during a speech in Sacaba, near Cochabamba. He wants to construct a highway that cuts right across the park, arguing that connecting isolated towns and communities is in the strategic interest of all Bolivians, including the TIPNIS indigenous people. But the inhabitants of the ancestral park strongly oppose the construction, and they are ready to fight against it.

"If the government wants to bring in heavy machinery to trample on our rights, they will surely start a conflict with us," says Mauricio Cuellar, one of their leaders. He regrets that, despite Morales' self-depiction as a protector of "Mother Earth" and the rights of indigenous people, the president wants to go ahead with a project which the TIPNIS residents say will lead to environmental degradation.

On the international stage, Morales is seen as a champion and one of the most vocal supporters of the environment. Last year, he hosted a climate change conference in the Bolivian city of Cochabamba, and Bolivia was the only dissenting country against the deal reached at international climate change talks in Cancún, whose terms it said were equivalent to "ecocide and genocide".

At the United Nations, it has also pushed for the recognition of access to clean water as a human right and, as a result of a Bolivian initiative, each 22 April is now marked as International Mother Earth Day.

Look closer to home, however, and a different picture emerges. "We're seeing an enormous contradiction between what he says and what the reality is," says Maria Lohman of Somos Sur [We Are the South], a Bolivian group that seeks to offer an alternative to a "dehumanising and predator model".

"What we see here is the plundering [of our resources]," says Lohman. "Each year, 740,000 acres go up in flames [to clear land for agriculture]." And the same plundering goes on unpunished in the mining sector, she argues. "The biggest mines are in the hands of transnational corporations which are looting minerals with the most anti-environmental methods."

Despite its finger-pointing at the west for causing climate change through the irrational use of raw materials, Bolivia's economy thrives on the sale of natural gas. "Domestically, the Morales administration has used the nationalisation of gas as one of its banner programmes," says Kathryn Ledebur of the Andean Information Network, a thinktank that promotes human rights and socioeconomic justice in Bolivia.

"Morales has emphasised that income from these industries has helped to fuel key initiatives, such as bonuses for schoolchildren and young mothers," says Ledebur. "Yet, this focus at times comes into conflict with the administration's international priorities: climate change and respect for the environment."

So, on one hand, Morales is Bolivia's first indigenous president and an environmental champion; on the other, he's a tacit supporter of the industrialised model. Daniela Leyton, a political psychologist for Kandire, an organisation that seeks the achievement of peace through the protection of human and environmental rights, believes that the president promotes these two conflicting sides interchangeably in his international image, to attract investment from abroad and ensure his political survival at home.

"If he needs to be accountable to international donors, we have an indigenous president," she says, referring to the huge foreign funds that aid programmes for Bolivia's indigenous people bring into the country. "But if he needs to be accountable to the people so that he can pay for social programmes and maintain a stable economy, we need large projects, and we're talking about hydrocarbon exploration above all."

For Leyton, the TIPNIS highway is a clear example of the president's double standards on the environment. Natural gas deposits have been found within the boundary of the park, and oil companies would need a road to exploit them. But stubbornly going ahead with its construction would alienate the president's indigenous support base, which would also be unpopular among Bolivia's international donors.

That is why Leyton believes that Morales can prevail only through honest and transparent consultation with all the indigenous communities in the TIPNIS – striking a balance between the two conflicting sides which is acceptable to all parties.