The lead attorney for the plaintiffs on Wednesday called the governor's action unprecedented.

"I've never seen anything like this," said Florida lawyer Michael Papantonio. "This just further delineates how badly the deck is stacked in West Virginia against people trying to recover when they're taking on DuPont. It's stacked against people who have been wronged by corporate America."

The jury in Harrison County Circuit Court last fall awarded damages totaling nearly $400 million to residents living near the former plant in Spelter. The plaintiffs argued the chemical giant spent decades downplaying and lying about health threats from arsenic, cadmium and lead that contaminated air, soil and water.

Punitive damages are designed to deter future misconduct, and the jury ruled that DuPont had engaged in wanton, willful and reckless conduct in its operation of the smelter. Non-punitive damages included $130 million to fund a 40-year health screening plan to monitor plaintiffs for any ailments related to exposure to chemicals.

Last week, DuPont appealed the entire verdict, arguing it has been unfairly punished for doing the right thing at the site and for the community. The state Supreme Court, which is in summer recess, has not yet indicated whether the appeal will be heard.

In a "friend of the court" brief filed last week, Manchin urged the justices to clarify what sort of appellate review is to be afforded DuPont under its constitutional right to due process. His lawyers cited a 2003 U.S. Supreme Court decision to argue that the 14th Amendment guarantees appeals of punitive damages.