(The Center Square) – A case regarding whether unions must refund fees collected from the paychecks of public sector employees who aren’t members will be heard by the U.S. Supreme Court.

The National Right to Work Legal Defense Foundation filed a reply brief in the class-action case Casanova v. International Association of Machinists, Local 701, and the case will be considered at the high court’s Oct. 9 conference.

The case is based on the 2018 Supreme Court case Janus v. AFSCME, which found public sector employees could not be forced to pay union fees as a condition of their employment. Unions can only deduct fees from employee paychecks if they provide affirmative consent.

Benito Casanova, a Chicago Transit Authority worker, is seeking a refund of fees she paid to the union from 2016 through 2018. The lead plaintiff in the Janus case, Mark Janus, is also seeking a refund of fees taken from his paycheck as far back as 2013.

Both cases will be considered Oct. 9.

The foundation said it is actively litigating about 20 cases that collectively seek to return an estimated $130 million in forced union fees “seized from workers in violation of the First Amendment,” according to a news release.

Earlier this month a report from the Illinois Economic Policy Institute found for the second straight year, the number of employees who are members of unions has declined. Since 2017, the report found union membership decreased in Illinois by more than 56,000 workers, according to data from the U.S. Department of Labor’s Bureau of Labor Statistics.