Hundreds of indigenous people began gathering in the Brazilian capital on Monday for a 10-day protest camp to defend their land rights and oppose a government bill in Congress that would allow mining and oil exploration on their reservations.

Organizers are hoping to gather 7,000 people from 200 of Brazil's 305 tribes to press Congress not to pass legislation proposed by far-right President Jair Bolsonaro that would open their protected lands to commercial mining and agriculture.

"We will not retreat," said Sonia Guajajara, head of the country's main indigenous umbrella organization, the Articulation of Indigenous Peoples (APIB) that represents most of Brazil's 900,000 indigenous people.

Warriors in feathered headdresses with their bodies painted with the black and red dyes of Amazon fruit seeds danced chanting ritual songs as they put up tents on the grassy esplanade next to government ministries in central Brasilia.

Bolsonaro has said indigenous people have too much land, holding up the development of the country, and vowed not to recognize an inch more of reservation lands. Environmentalists say the reservations save the rainforest from destruction.

Guajajara said 13% of Brazil's territory is protected indigenous reservation land, with 98% of that in the Amazon region. But 400 indigenous communities are still struggling to get their ancestral lands recognized.

Bill 191 is being fast-tracked in the lower house of Congress by lawmakers allied to the government who argue that it is needed to extract potash for fertilizer for Brazil's grain crops that depend on imports disrupted by the Ukraine war.

The legislation, backed by the powerful farm lobby, would also allow hydroelectric dams to be build on indigenous lands.

Guajajara said at a news conference APIB will campaign to get more indigenous people elected to Congress in this year's general election. At present, there is only one indigenous representative, Congresswoman Joenia Wapichana.

"We need to increase our voices in Congress," said Guajajara.

Guajajara said she will stand for the left-wing PSOL party representing Sao Paulo, Brazil's largest city.