A worker choice advocacy group filed a legal brief Monday against a union lawsuit which looks to upend West Virginia’s right-to-work law.

West Virginia became the most recent state Feb. 12 to enact a right-to-work law. The policy outlaws mandatory union dues or fees as a condition of employment. The National Right to Work Foundation (NRTW) provided a legal brief defending the policy in a lawsuit brought by some local unions.

“West Virginia union bosses are asking the Kanawha Circuit Court to reject over 60 years of legal precedent,” NRTW President Mark Mix said in a statement provided to InsideSources. “West Virginia’s Right to Work law should not be overturned on the basis of an outrageous and rejected legal theory advanced by union lawyers.”

The West Virginia AFL-CIO brought forth the lawsuit May 8 against the state law. The suit claims the law puts unions in an unlawful and unjust position. Labor unions that become the bargaining agent for a workplace are required by law to represent every workers whether or not they pay dues.

“We maintain that such a Right to Work law generally violates the West Virginia Constitution’s prohibition of taking property without due process and compensation,” West Virginia AFL-CIO Secretary-Treasurer Josh Sword said in a statement. “But we also believe that, based on the specific definitions within the legislation of whom the provisions apply to, no private-sector contracts will be affected, regardless of a court ruling on its constitutionality.”

Right-to-work supporters argue its not about hurting unions but about providing workers a choice. Many simply don’t want workplace representation or the benefits the union fights for. States that have right-to-work policies might also attract businesses because employers don’t have to deal with union interference or expenses.

Republicans in West Virginia made right-to-work a priority soon after securing the state legislature in November 2014. The measure was introduced Jan. 13 on the first day of the 60-day legislative session. Republicans held a slight majority in the legislature, allowing it to pass despite adamant opposition from Democrats.

Righttowork laws in multiple states have faced numerous lawsuits over the decades. Nevertheless the policy has been upheld over the years as a federal protected states right under the 1947 Taft-Hartley Act. The law has passed in 26 states with West Virginia being the latest.

Democratic Gov. Earl Ray Tomblin vetoed the measure when it was originally passed by the legislature. The state law gave Republicans just enough of an advantage to override it. West Virginia lawmakers only needed a simple majority unlike most states which require to a super majority of two-thirds to override a veto.

Labor unions have since held protests against the policy. Other groups have fought to defend the law. Americans for Prosperity West Virginia launched a media campaign in support of the policy. The free-market advocacy group also sent out letters urging lawmakers to support the measure.

The West Virginia AFL-CIO did not respond to a request for further comment by InsideSources.