A federal judge in Miami agreed with environmental groups and an Indian tribe Wednesday to appoint an expert to monitor Everglades pollution cleanup, in a defeat for the Bush administrations in Washington and in Tallahassee.

Government agencies and politically powerful sugar growers vigorously objected to the appointment of a special master to consider whether an 11-year-old Everglades restoration pact is being violated or will be soon.

''To delay action would be irresponsible,'' U.S. District Judge Federico Moreno said in an order issued after business hours. The special master ``will offer additional assurance that the Everglades cleanup will proceed in a timely and efficient fashion.''

An environmental lawyer to be named to the post in two weeks will supervise all sides, examine the complex science, monitor cleanup construction projects and report back to the court.

''This is a major milestone and a big step forward for protection of the Everglades,'' said David Guest, attorney for conservation groups.

Calls seeking comment from the U.S. Justice Department, the Florida Department of Environmental Protection and growers were not immediately returned.

''This will force true consideration of the real issues,'' said Dexter Lehtinen, attorney for Miccosukee Indians, who live in the Everglades. A special master will ``address the difficulties rather than sweep them under the rug, which is what the government wanted to do.''

The judge said he had not decided whether anyone is violating the 1992 settlement of a federal lawsuit against the state but noted the tribe has offered ''credible documentary evidence'' to prove violations are plausible.

The federal and state governments have agreed to an $8 billion restoration project, and Gov. Jeb Bush has pledged his ''unwavering'' commitment to the work.

The tribe maintains state water managers are sending too much phosphorus into the federally protected areas and are building cleansing marshes too slowly to meet a 2006 deadline.

The settlement limits the flow of phosphorus from farms and suburbs into the Everglades. The fertilizer ingredient feeds exotic plants that drive out native animals. The agreement is intended to restore the Everglades to its days as a free-flowing, slow-growth marsh.

Moreno held his first hearing in the case earlier this month after the sugar industry won its bias claim against the judge who supervised the lawsuit for 15 years. The final act by U.S. District Judge William Hoeveler was to decide a special master was needed.