D.C. residents could see a rise in the minimum wage to $15 an hour by 2020 under two separate paths: legislation introduced by Mayor Muriel Bowser in April, or a referendum that hasn’t yet been approved for the November ballot.

The major difference between the two is the issue of tipped workers: Bowser’s bill would increase the tipped-minimum wage (what employers are required to pay servers before tips are taken into account) from $2.77 an hour currently to $7.50 by 2022, while the proposed ballot measure would get rid of it by 2025, such that there’d only be one minimum. By law, businesses have to pay tipped workers the general minimum wage if the addition of tips does not get up to it.

Now, as the D.C. Council plans to hear testimony on the mayor’s legislation on Thursday, a new report by the National Women’s Law Center urges policymakers to create what it and other advocates call “one fair minimum wage,” like the ballot initiative would phase in over time. The group finds that the lower minimum wage for tipped workers in general leaves women behind, citing data from the U.S. Census Bureau and the Department of Labor. Twenty-two percent of female tipped workers in the District live in poverty, according to the report—”double the rate for men tipped workers (11 percent), and more than twice the rate for working women and men overall,” 9.3 and 6.8 percent, in turn.

“Providing the same minimum wage for tipped workers would ensure a more stable and adequate base income for those workers,” the report says. “In the states where employers must pay their tipped workers the regular minimum wage before tips, the average poverty rate for women tipped workers is 33 percent lower—and the average gender wage gap is 14 percent smaller—than in states with a $2.13 tipped minimum cash wage [which is the federal tipped minimum wage]. These gains have not come at the expense of business; the states with one minimum wage for all workers have experienced higher restaurant sales per capita and greater growth in restaurant industry jobs than the states with lower minimum wages for tipped workers.”

Among the report’s other findings: 28 percent of female restaurant servers and bartenders in D.C. live in poverty as compared with their male peers; a boost in the minimum wage to $15 an hour would mostly benefit workers of color. (The Economic Policy Institute released a report last month that contained similar findings and is cited by the NWLC.)

Still, local restaurant owners and some servers have challenged the elimination of the tipped-minimum wage as bad for business and bad for workers. Getting rid of it, some say, would force restaurants to raise prices or say bye to tips. The tension between proponents of the ballot initiative and Bowser’s legislation will likely manifest itself at the D.C. Council’s hearing on Thursday, which is being held by the Committee on Business, Consumer, and Regulatory Affairs.

You can read the NWLC’s report here.