Just months before U.S. President George Bush leaves office, his administration is proposing changes that would allow federal agencies to decide for themselves whether subdivisions, dams, highways, and other projects have the potential to harm endangered animals and plants.
The proposal would cut out the advice of government scientists who have been weighing in on such decisions for 35 years.
Agencies also could not consider a project's contribution to global warming in their analysis.
Democrats and environmental groups reacted swiftly to the news.
Senator Barbara Boxer, a Democrat from California and head of the Senate's environment committee, said Bush's plan is illegal.
Environmentalists complained the proposals would gut protections for endangered animals and plants.
Chairman of the House committee that oversees the Interior Department, Representative Nick Rahall, a Democrat from West Virginia, said he was "deeply troubled."
"This proposed rule ... gives federal agencies an unacceptable degree of discretion to decide whether or not to comply with the Endangered Species Act," Rahall said.
Interior Secretary Dirk Kempthorne defended the revisions, saying they are needed to ensure that the Endangered Species Act is not used as a "back door" to regulate the gases blamed for global warming.
"Focus Our Efforts"
If approved, the changes would represent the biggest overhaul of endangered species regulations since 1986.
They would also accomplish through rules what conservative Republicans have been unable to achieve in Congress: ending some environmental reviews that developers and other federal agencies blame for delays and cost increases on many projects.