President Bush on Wednesday moved to exempt Navy sonar training missions off Southern California from complying with key environmental laws, an effort designed to free the military from court-ordered restrictions aimed at protecting whales and dolphins.

The president's directive was designed to short-circuit a long-running battle in which environmental groups have won court victories that frustrated the Navy's preparations for nine training missions over the next year, the first one set to begin next week.

The battle pits concerns over injuries to marine mammals against troop readiness and national security. But with Bush's latest action, it took on overtones of a struggle between the administrative and judicial branches of government.

U.S. District Judge Florence-Marie Cooper in Los Angeles, who ordered the restrictions, has called the Navy's plans "grossly inadequate to protect marine mammals from debilitating levels of sonar exposure."

By contrast, the Navy asserts that it's already doing enough to safeguard marine mammals from harmful effects of the mid-frequency active sonar it uses to hunt for quiet diesel-electric submarines now operated by Iran, North Korea and dozens of other countries.

In a memo justifying his action, Bush did not address environmental concerns. He said his decision would "enable the Navy to train effectively" for activities "which are essential to national security" and "in the paramount interest of the United States."

The White House directive, issued late Tuesday and released Wednesday, set off a daylong rush through federal courthouses by Justice Department attorneys and lawyers for environmental groups.

"We will vigorously oppose the president's illegal waiver of federal law," said Joel Reynolds, a senior attorney with the Natural Resources Defense Council. Bush's action was "an end-run" around the nation's environmental laws, Reynolds said.

The complex legal situation involves two federal environmental laws and Cooper's court order. One law, the Coastal Zone Management Act, is designed to protect coastal and marine resources, including whales and other marine mammals. It has a provision allowing the president to exempt certain federal activities from the law's limits, said Peter Douglas, executive director of the California Coastal Commission.

The other law cited by environmental groups, the National Environmental Policy Act, does not give the president such unambiguous power.

Neither does Bush have the legal power to overturn a federal court order. So Justice Department lawyers followed his move with legal papers asking the federal courts to remove the order, which was a preliminary injunction that imposed an array of restrictions on the use of sonar, including its shutdown when marine mammals ventured within 2,200 yards of sonar devices.

The Navy indicated Wednesday that it will not proceed with its training missions unless the injunction is set aside.

The Justice Department, representing the Navy, asked a three-judge panel of the U.S. 9th Circuit Court of Appeals to set aside the restrictions by Friday.

Justice Department lawyer Allen M. Brabender said Cooper's order "profoundly interferes with the Navy's global management of U.S. strategic forces, its ability to conduct warfare operations, and ultimately places the lives of American sailors and Marines at risk."

"Each day that the injunction remains in force the Navy and national security suffer grievous harm," Brabender wrote.

The appeals court responded late Wednesday by sending the case back to Cooper, saying the Navy needed to ask her first. Lawyers for the Navy plan to ask the judge to issue a decision by this afternoon.

Meanwhile, the plaintiffs were left watching a legal ping-pong match, hoping they would get a chance to weigh in on the case.

Coastal Commission director Douglas said he found the Bush directive "troubling" and "another example of this Republican administration overriding environmental protections under the banner of fear."

The commission, Douglas said, has no clear way to fight Bush's action, the first presidential override of the coastal management law that since 1972 has given states the right to review federal activities that affect their coastal resources.