A year after they walked out asking for higher wages and lower healthcare costs, the state’s teachers unions are set to strike again, starting Tuesday. The dispute has been created by the State Senate’s proposed amendment to a funding bill that would create charter schools and offer education savings accounts, a type of school voucher. If passed, the bill would also reduce the amount of funding available to traditional public schools.

West Virginia Senate President Mitch Carmichael said: “I think it’s a moral imperative for us to instill competition and flexibility and achievement into the school system.” In response, teacher unions say senators have been influenced by advocates for charter schools and vouchers from outside of the state and that they’ve failed to speak to anyone working in education in West Virginia about the amendment.

Tuesday’s state-wide walkout marks almost a year to the day since West Virginia education workers went on strike on February 22, 2018. Since that first walk out, teachers have taken to picket lines in Oklahoma, Kentucky, and Arizona, as well as a widespread strike in North Carolina and citywide strikes in Los Angeles and Denver. Teacher strike action contributed to the largest increase in labor action the U.S. has seen in decades, according to the Bureau of Labor Statistics

This week, as the West Virginia anniversary approaches, teachers in Oakland, California, are also set to strike starting Thursday.