"This government represents one of the biggest-ever reversals for Brazilian environmental policy," said Jovino Candido, one of seven Green Party members in the lower House of Deputies who withdrew support from the ruling coalition in Congress.

The Green Party has only a tiny fraction of the 513 deputies in the lower house, but its departure marked another political setback for Lula as he tries to rebuild support after a string of defeats.

Brazilian Culture Minister Gilberto Gil, a member of the Green Party, was in Cannes, France and not immediately available to comment on his plans, a spokesman said.

Lula entered office in 2003 on high hopes he would control use of threatened Amazon areas and balance needs for environmental protection with economic growth.

After 28 months in office environmentalists say he has done more to promote dams, roads and farming in the Amazon than halt destruction of the world's largest rainforest, which is home to up to 30 percent of the world's plant and animal species.

Environmentalists have applauded Lula's efforts to create vast Amazon reserves to promote sustainable use of timber and land resources but they have criticized his inability to enforce environmental laws protecting the vast jungle.