With war looming in Iraq, the Bush administration this week asked Congress to exempt the Defense Department from a broad array of environmental laws governing air pollution, toxic waste dumps, endangered species and marine mammals.

The Pentagon says it needs the changes to ensure unfettered training and readiness activities, and to provide the military with relief from environmental regulations that protect endangered species and critical habitats on millions of acres of military training ranges across the country.

But, in some cases, the plan would also grant state officials greater flexibility in meeting federal clean air standards if they can demonstrate there was a sudden influx of jet fighters, tanks and other military hardware that added to the overall air pollution.

Congress rejected most of these proposals last year when they were floated at the last minute by the Pentagon. But this time the administration is moving early to promote them, and the House and Senate armed services committees are giving them prompt attention by scheduling hearings for next week.

The proposed changes, which began circulating on the Hill late Monday as part of the 2004 defense authorization bill, is certain to trigger a bruising battle pitting Pentagon officials and their allies in Congress against environmentalists and Democrats who fear a major rollback of some of the country's most important environmental laws.

Defense officials contend that their plan is designed to strike a "common sense" balance between environmental stewardship and wartime readiness.

"Fundamentally, these proposals are designed to ensure that the Defense Department can execute its military missions while still protecting the environment," a senior Pentagon official said yesterday. "They are mostly designed to confirm existing and longstanding policies that are under challenge in a variety of court cases."

A senior administration official said each of the proposed changes "is tailored toward giving [the Pentagon] a more flexible management path to meet the statutory objectives."

But Michael Jasny, a senior policy analyst for the Natural Resources Defense Council, charged that "[t]his bill is a rollback of almost every major environmental law on the books."

Critics of the administration plan say it is not necessary, because the Pentagon has not made a compelling case that the laws on the books have impeded readiness activities, and because existing regulations already can be waived in the interests of national security.

A General Accounting Office report on military training issued in June found that "[t]raining readiness, as reported in official readiness reports, remains high for most units" and that readiness data do not support the Pentagon's claims that it is being hurt by the encroachment of environmental laws.

EPA Administrator Christine Todd Whitman said last week in testimony before the Senate Environment and Public Works Committee, "I don't believe that there is a training mission anywhere in the country that is being held up or not taking place because of environmental protection regulation."

Rep. John D. Dingell (Mich.), the ranking Democrat on the House Energy and Commerce Committee, said the military for years has been trying to "get out from under" environmental laws. "But using the threat of 9/11 and al Qaeda to get unprecedented environmental immunity is despicable," he said.

Rep. Nick J. Rahall II (W.Va.), the senior Democrat on the House Resources Committee, said existing exemptions "have worked quite well to ensure that our armed services remain combat-ready and that our homeland environment remains safe and healthy."

The administration plan is designed to provide the Pentagon with exemptions from or loopholes in the Clean Air Act, the Endangered Species Act, the Superfund law, the Resource Conservation and Recovery Act and the Marine Mammal Protection Act when they affect readiness activities.

The changes in the clean air law would broaden the definition of "training" to exempt even nonmilitary activities, such as driving vehicles on military bases or from one training site to another, and the spraying of pesticides on a right of way. They would also eliminate time lines for the military to estimate the quantity of military emissions in air quality nonattainment areas.

The change in the marine mammal law would address a contentious dispute between environmentalists and the Navy over the use of a low-frequency active (LFA) sonar system that is suspected as the cause of numerous whale beachings in recent years. Last fall, a federal judge enjoined the Navy from deploying the system pending a trial.

Staff writer Juliet Eilperin contributed to this report.

EPA chief Christine Todd Whitman, left, said she doesn't believe there is any U.S. military training "being held up . . . [by] environmental protection regulation." Rep. Nick J. Rahall II (D-W.Va.) said existing exemptions "have worked quite well."