In the latest legal assault on the Playa Vista development, project opponents are seeking a federal injunction to halt bulldozing and other work on 16 acres of wetlands on the site as part of a larger action that aims to take the case to the U.S. Supreme Court.

The Wetlands Action Network and California Public Interest Research Group are asking U.S. District Court Judge Ronald Lew to halt the work as they seek to overturn an Aug. 21 decision by a federal appeals court.

That decision, by a three-judge panel of the Ninth Circuit Court of Appeals, reversed a 1998 ruling by Lew that the U.S. Army Corps of Engineers erred in issuing a permit allowing the 16 acres to be disturbed without ordering an extensive environmental review of the entire mixed-use project.

In making the decision, the Ninth Circuit dissolved a prior injunction issued by Lew prohibiting any work on the 16 acres, portions of which are critical for the creation of a fresh-water marsh that would treat project runoff.

The project opponents say they are seeking the injunction to protect “every acre” of wetlands at the site while they press the Supreme Court to consider the larger issue of whether a federal environmental impact statement should be prepared. Having an EIS performed could delay the entire project for three years, said Marcia Hanscom, executive director of the wetlands group.

“(Performing an EIS) is a massive undertaking,” Hanscom said.

In response to the legal action, Coby King, a spokesman for Playa Vista, said the developer is “not going to speculate on something that isn’t likely to occur.” But in legal papers, attorneys for the developer said the injunction would halt work valued up to $45 million on the site.

The opponents have hired prominent Washington, D.C. environmental attorney Bruce Terris to press their case, but they acknowledge the odds of the high court taking the case are small. The Supreme Court hears only a fraction of the appeals it receives each year.