A union front group leading the charge for higher fast food wages is recruiting unpaid workers to advance its agenda.

Raise Up for $15, an advocacy group backed by the Service Employees International Union (SEIU), posted an advertisement on Idealist.Org in search of a "pro bono wage theft advocate."

"This summer workers are standing up against the wage theft epidemic in the fast food industry by suing their employers for unpaid wages," the ad says. "We are looking for law students and pro bono attorneys who will be in the Triangle region of North Carolina this summer (late May to late July) to represent our workers in small claims court."

Applicants are expected to work for 10 hours per month without pay and are invited to submit their resumes to an SEIU organizer. The group’s mission statement slams fast food companies for failing to pay workers a just salary.

"We believe that people who work hard for a living should make enough to support themselves, their families and their neighborhoods—and that workers should be treated with dignity and respect," the site’s About Me page says.

The group is working to ease unionization of fast food franchises and boost entry-level wages to $15 an hour. "We can’t survive on $7.25," the site says, referring to the current federal minimum wage.

Ryan Williams, a labor watchdog at Worker Center Watch, said he found it curious that the group can operate with such a slogan on the backs of unpaid labor.

"Workers Organizing Committees such as Raise Up NC, which operate under minimum wage banners when it suits their interests, are seeking activists to attack employers for wage theft and unpaid wages. In the case of Raise Up NC the ‘wage theft advocate’ position doesn't pay anything," he said.

Unions and labor activists have long described unpaid internships as exploitive. Former SEIU attorney Michael Oswalt lamented the lack of protections that workers, especially college interns, face when they take on unpaid work in 2010.

"There is no internship exemption in [federal law]," he told the UTEP Spectator. "Interns are in an extremely vulnerable position. It is very difficult for them to file a complaint."

The SEIU and Raise Up for $15 are not the first restaurant worker advocates to employ unpaid workers to advocate for higher wages. The Restaurant Opportunities Center, a nonprofit union front group, has also posted job ads seeking unpaid workers to fight wage theft.

Capitol Hill Democrats have also found themselves embroiled in controversy over supporting minimum wage hikes while failing to pay their interns a living wage. A 2013 Employment Policies Institute analysis revealed that 97 percent of Democrats supporting President Obama’s $10.10 minimum wage employ unpaid interns.

"The SEIU's nationwide campaign to organize fast food workers includes the creation of Workers Organizing Committees, as well as widespread protests decrying the industry's wages and benefits," Williams said. "These groups have sought free labor while attacking businesses for their labor practices."

The Carolina Workers Organizing Committee, which sponsors the Raise Up for $15 campaign, did not return calls for comment.