OLYMPIA, Wash. (AP) — Some lawmakers in Olympia say Washington state needs to tax sales of medical marijuana, just as it will tax sales of recreational marijuana if and when legal sales begin in the state.

Democratic Reps. Ross Hunter of Medina and Reuven Carlyle of Seattle introduced a bill Thursday that would tax marijuana sales from dispensaries 25 percent. They say it’s important to have similar tax rates to keep prices consistent and not drive nonmedical users to the medical dispensaries.

Last fall voters passed Initiative 502, setting up a system of state-licensed growers, processors and retailers. The U.S. Justice Department is weighing whether to sue to block the state-licensed sales from happening.

Meanwhile the state Liquor Control Board is developing rules for the legal market, with sales set to begin at the end of the year. I-502 calls for recreational marijuana to be taxed 25 percent at three stages, when it’s transferred to processors, stores and customers.