Labor unions representing federal workers are facing another challenge to collective bargaining rights – and even their very existence – in a newly introduced Republican bill meant to prevent American taxpayer dollars from subsidizing union costs.

The Federal Workforce Freedom Act would prohibit federal employees from organizing or joining labor unions in order to collectively bargain, as well as forbid federal agencies from participating in collective bargaining negotiations with labor unions representing federal workers.

The bill, introduced Thursday, would also terminate any and all collective bargaining agreements between labor unions and federal agencies “established before, on, or after the date of enactment of this bill.”

The sponsors of the bill, U.S. Sens. Mike Lee, R-Utah, and Marsha Blackburn, R-Tenn., argue that these kinds of collective bargaining agreements harm worker efficiency, increase labor costs, and charge taxpayers in the bargaining process.