The anti-Wal-Mart crusader leading the fight to unionize the company once threatened a non-union janitorial company with death threats, The Daily Caller has learned.

Dan Schlademan runs the United Food and Commercial Workers Union’s (UFCW) Making Change at Walmart group, which is fighting for pay hikes for Wal-Mart employees and to block the retail giant from opening new stores that could drive down wages in various regions. The Making Change at Walmart campaign is organizing employees at every stage of the Walmart supply chain, including logistics and warehouse workers.

Schlademan made the threat in a phone call to the president of Houston’s Professional Janitorial Services (PJS) while Schlademan was working for the Service Employees International Union (SEIU). Schlademan ran the SEIU’s Justice for Janitors campaign in Houston in 2006. The phone conversation was captured on tape.

PJS, which Schlademan threatened while working for SEIU, was recently subjected to federal Occupational Safety and Health Administration (OSHA) site visits on which SEIU representatives joined government OSHA inspectors. PJS, despite SEIU pressure, is still a nonunion company.

“Brent, I want you to understand something. I’m your one defender. Everyone else is saying ‘Let’s go kill PJS,’” Schlademan told PJS’ president in a phone call.

Schlademan later acknowledged his use of death threats in a March 13, 2008 oral videotaped deposition in a PJS defamation lawsuit against SEIU reviewed by The Daily Caller.

An opposing lawyer asked Schlademan if “there were folks at the union that wanted to hurt or harm PJS?”