Missouri Governor Eric Greitens signed a bill [text] into law on Monday, making Missouri the most recent right to work state. The law, which will go into effect August 28, prevents employers from requiring union membership or dues to support a union as a condition of employment, making it a misdemeanor to do so. Missouri will become the twenty-eighth state to have right to work legislation when the law goes into effect. Greitens signed the bill just weeks into his first term. Former governor Jay Nixon vetoed [St. Louis Post-Dispatch report] such a bill in 2015.

The Missouri branch of the labor union the AFL-CIO issued vowed to fight the measure, filing a referendum [Kansas City Star report] to overturn it. Right to work laws have become more prevalent across the country in recent years. Earlier this month the Kentucky House of Representatives advanced a bill [JURIST report] that would allow workers to avoid paying dues at union workplaces. The West Virginia legislature passed the WV Workplace Freedom Act in February 2016 [JURIST report], overruling a veto by the Democratic Governor Earl Ray Tomblin the day before. West Virginia became the twenty-sixth state in the country with a right to work law. In May the Wisconsin Court of Appeals stayed [JURIST report] a lower court’s decision striking down Wisconsin’s “right to work” law, thus reinstating it at least for the time being.