Lawyers for hundreds of workers from India who claim they were subjected to abusive conditions at Gulf Coast shipyards after Hurricane Katrina are asking a federal judge to certify their lawsuit as a class action against the company that hired them.

The Southern Poverty Law Center, American Civil Liberties Union and other groups filed a class-action suit in 2008 on behalf of seven individuals who worked for Signal International, an oil rig construction and repair company.

The plaintiffs' lawyers on Tuesday asked U.S. District Judge Jay Zainey to certify the case as a class action for roughly 500 workers who claim they were lured here after the 2005 storm with the false promise of green cards and then forced to live in crowded, unsanitary conditions.