Two former McDonald's store managers have come forward to admit making staff work without pay.

The former managers said they felt pressure from corporate to cut labor costs, so they engaged in some illegal practices, such as asking employees to clock out and continue working.

They came forward on behalf of Fast Food Forward, an advocacy group fighting for better pay and working conditions for fast food employees. The group has received funding from the Service Employees International Union.

"I, on several occasions, had employees come and work either before their shift or stay after their shift," Kwanza Brooks, a former McDonald's manager for 10 years in Maryland and North Carolina, said in a video produced by Fast Food Forward. "I have had employees literally clock out to work because they were either going into overtime or labor [costs were] getting extremely high."

Lakia Williams, a former assistant manager at a McDonald’s in Charleston, S.C., said she made adjustments to time sheets to avoid exceeding the company's strict limitations for labor costs.

"There was so much pressure," she said in an interview with Bloomberg. "It’s not only the franchisees group and the general managers, it is corporate. It’s something internal, it’s something deeper, and it’s something that has been going on for years."

McDonald’s said in an e-mailed statement that it is committed paying its employees correctly.

"When McDonald’s learns of pay concerns in restaurants which we own and operate, we review the concerns and take appropriate action to resolve them," the statement reads. "We trust that our independent owner-operators do the same."

The former managers came forward following a series of worker lawsuits brought against McDonald's franchise owners alleging that they systematically withheld pay. One of the accused franchise owners has agreed to pay nearly $500,000 to current and former employees as a result of one of the lawsuits.

Since 1985, McDonald's has been found in violation of the Fair Labor Standards Act and had to pay back wages more than 300 times, according to CNN.

