The 9th U.S. Circuit Court of Appeals in San Francisco Dec. 6 deferred judgment on a request by labor and environmental groups to block Mexican trucks from gaining broader access to U.S. roads.

The Bush administration lifted the ban on Mexican trucks last week. In doing so, it said expanding the operations of Mexican trucks in the United States would not hurt the environment.

However, the Teamsters union and Ralph Nader's consumer watchdog group, Public Citizen, are among those who claim the administration skirted environmental regulations in lifting the ban on long-haul trucks.

They sought an emergency stay to block the new policy and requested a new environmental review of how older diesel trucks operated by some Mexican firms would affect air quality.

The plaintiffs have argued that Mexican trucks will increase pollution because they don't have to meet U.S. emissions standards. The same groups sued the department in May in U.S. District Court, claiming the Bush administration failed to assess the environmental effect of allowing Mexican trucks throughout the United States.

But the Transportation Department has only just begun reviewing more than 100 applications from Mexican trucking firms that want long-haul authority. The government told the court it could be at least a month before the first permit is granted.

The court, which took the case under advisement, said it would consider the issue further once the agency was ready to grant permits or when the administration and the Mexican government agreed on the role of U.S. safety inspectors in Mexico.