"He is a little weak, but lucid, asking the government to practice what it has preached in the past," Roberto Saraiva, of the Indigenous Mission Council, told Reuters.

The project would divert the river through a 440 mile (700 km) network of canals to irrigate large areas of Brazil's dry, poverty-stricken northeast.

Cappio and other critics say the $2 billion plan will benefit big business rather than help the poor. He has vowed to fast until death unless President Luiz Inacio Lula da Silva cancels it.

The bishop has sustained himself only by drinking water from the 1,700 mile (2,700 km)long river, which runs from Minas Gerais state to the Atlantic Ocean.

Buses of faithful have been arriving in the little town of Cabrobo, in Pernambuco state, a few miles from the Sao Sebastiao chapel where Cappio has based himself.

A crowd marched in a procession to the chapel on Tuesday to hear a mass officiated by Cappio and Bishop Tomas Balduino, president of the Pastoral Land Commission.

Vigils were also held in other cities such as Belo Horizonte and Porto Alegre as support for the bishop began to spread across this vast nation, the world's largest Roman Catholic country.

He has received backing from various churchmen, human rights groups and environmentalists in Brazil and overseas, Saraiva said.

Cappio, who has fought to protect the river and its communities for 30 years, began the strike nine days ago when the project won environmental authorization.

The plan aims to provide water to 12 million people and is meant to create jobs and stem the flow of poor Brazilians from the northeast to richer southern cities.

Critics say the huge canals to transport water across five states are costly, unnecessary and aimed at promoting Lula's possible reelection in 2006. Cappio proposes smaller projects to store and distribute water for the rural poor.

Around 70 percent of the water from the current plan will go for production of shrimp, grapes, flowers and other farm exports. About 4 percent will go to the homes of poor families in arid areas.

On Saturday, Lula sent an emissary to Cabrobo to open a dialogue with the bishop. In a letter, Cappio thanked Lula but said he would only end his hunger strike if the project was halted.

Lula, speaking to factory workers in Sao Paulo on Monday, said: "If it depends on my willingness to talk, to discuss, I will make every effort to see if we can find a solution."