Low-wage workers are trying something new to improve conditions in warehouses that sprawl across suburban Will County. A class-action lawsuit claims two contractors at a massive Wal-Mart Stores distribution center in Elwood violated a federal law requiring most companies with 100 or more employees to provide 60 days’ notice of a mass layoff.

The suit, filed Wednesday in U.S. District Court for the Northern District of Illinois, claims a logistics firm and staffing agency violated the Worker Adjustment and Retraining Notification Act by failing to provide the notice before laying off about 65 workers in the warehouse December 29.

On paper, the plaintiffs were employees of a staffing agency, Florida-based Eclipse Advantage, that was brought in by Wisconsin-based Schneider Logistics, a company that runs the warehouse. Wal-Mart owns the facility, hired Schneider and owns the goods the workers unloaded, but the suit does not name the Arkansas-based retailer as a defendant.

It’s not uncommon in the retail industry for companies to shed workers as the holiday season winds down. Wednesday’s claim, nevertheless, says the layoff came in retaliation for a November suit alleging wage and hour violations at the warehouse. That case’s defendants are Schneider, Eclipse and another staffing agency, Mid-West Temp Group, based in southwest suburban New Lenox.

Dizzying as the warehouse’s labor arrangements may be, plaintiffs in Wednesday’s suit say just one company is ultimately responsible.

“Wal-Mart hires third parties or agencies because they’re always trying to save money to see how they can get the job done with less costs,” said Leticia Rodríguez, 36, who worked in the warehouse for five years through staffing firms. “We as employees pay the price because we’re forced to work under conditions like this — [for less than] minimum wage sometimes — because we need to make ends meet.”

In response to the plaintiffs, Wal-Mart spokesman Greg Rossiter read a prepared statement: “We hold all of our vendors to high standards, and our expectation is they comply with all applicable laws. Our vendors, such as Schneider, may take whatever corrective actions may be necessary.”

Rossiter declined to say how Wal-Mart holds venders like Schneider accountable.

Schneider, for its part, didn’t return calls and messages about the suit.

Kristina Sanders, human resources manager of Eclipse, declined to answer questions. She read a prepared statement that said her company “has and will continue to pay its employees in compliance with all applicable laws at competitive rates.” She said any allegations of unlawful pay or practices were “unfounded” and would be “defended vigorously.”

The suit claims the plaintiffs were “jointly employed” by Eclipse and Schneider because, among other reasons, both companies directed the work.

“First thing in the morning, Schneider requires all the employees in this section of the warehouse to line up and start doing stretches to avoid workplace injuries,” said Christopher Williams, the plaintiffs’ attorney. “So the Schneider employees are standing next to the Eclipse employees, [who] are standing next to the Mid-West employees. And they are all doing these stretches together under the supervision and control of Schneider.”

It’s unusual to sue a staffing agency based on the WARN Act, designed to provide workers time to adjust to layoffs, get training to compete in the job market, and find other employment.

The November suit, in contrast, is part of a wave of litigation targeting “wage theft,” in which employers allegedly flout the minimum wage, shortchange workers on overtime or force them to work off the clock.