The federal government’s top labor arbiter may use its regulatory power to force non-union employees in right to work states pay union dues.

The National Labor Relations Board (NLRB) put out a call for legal briefs on Wednesday asking labor law scholars to weigh in on whether unions should have the ability to extract dues payments from non-members. The announcement drew immediate criticism from right to work activists.

"It is unfortunately not surprising that the Obama NLRB is now actively working to undermine the 25 state Right to Work laws. Its ‘call for briefs’ signals this NLRB’s intention to reverse over 60 years of Board precedent to give union bosses an unprecedented tool to eviscerate employees’ Right to Work protections," Mark Mix, president of the National Right to Work Committee, said in a release.

"Right to work" laws ban coercive dues systems in which employees must join a union and pay dues as a condition of employment. The laws have passed in 25 states and are spreading in traditional union strongholds: Wisconsin, the birthplace of public sector unions, passed such a law in March, just two years after similar regimes were implemented in Indiana and Michigan.

Unions have fought the law in courts in nearly every state that has adopted the measure, arguing that since labor groups negotiate wages and benefits on behalf of all workers, non-members are "free-riding." In most cases, those challenges have not prevailed in state or federal courts. Unions in Indiana, for example, filed a flurry of lawsuits intended to block the implementation of the state right to work law. Federal Judge Phillip Simon tossed them out of court in 2013.

"None of the legal challenges launched by the union here to attack Indiana’s new Right to Work law can succeed," he wrote. "The electorate can ultimately decide whether [lawmakers’] judgments are sound, wise, and constitute good governance and can express their opinions at the polls and by other means. But those are questions beyond the reach of the federal court."

The call for briefs followed a ruling from NLRB Administrative Law Judge William Nelson Cates, who famously sanctioned Hooters for a rigged bikini contest. Cates upheld right to work exceptions, striking down a "fair share" policy. The local AFL-CIO affiliate in the case petitioned the board to reconsider.

"The [union] asks the Board to adopt a rule allowing unions to charge nonmembers a fee for grievance processing," the NLRB said in its call for briefs. "If such fees were held lawful in principle, what factors should the Board consider to determine whether the amount of such a fee violates [existing labor law]? What actions could a union lawfully take to ensure payment?"

Mix sees the NLRB’s effort as another regulatory handout to unions that have been unsuccessful in winning democratically.

Rather than re-litigating right to work laws that have survived decades of legal challenges, he said policymakers should reconsider the monopoly bargaining status unions enjoy. If employees could negotiate or file grievances separately, there would be no free rider problem, according to Mix.

"The real solution would be to strip union officials of their monopoly bargaining powers that let them impose unwanted ‘representation’ on unwilling workers," Mix said. "As long as union bosses are empowered to force nonmembers under their contracts, Right to Work laws should continue to protect workers from being forced to subsidize that unwanted union boss monopoly representation, including through the union-imposed grievance process."

Briefs must be submitted by June 1.