On July 1, D.C.’s long-awaited paid family leave law will take effect, giving hundreds of thousands of private-sector workers in the city up to eight weeks of paid time off to care for a newborn child, six weeks to attend to a sick family member, and two weeks to address personal medical issues.

But advocates of the new law—the first of its kind in the region, and one of only a handful across the U.S.—worry that it could leave a large number of people without access to paid leave.

Final regulations written by the city on how the law will be implemented specify that anyone seeking paid time off has to be employed at the time they apply for and then receive the benefits, which include wage replacement of up to $1,000 a week. In a written explanation to the D.C. Council, the Department of Employment Services—which will oversee and run the leave program—says it’s a reasonable interpretation of the law’s intent.

“The law is silent on whether an individual must be currently employed to receive [paid family leave] benefits,” it says. “The law does contemplate that someone is taking time off from work in order to receive benefits, suggesting that there must be a connection to work in order to receive benefits.”

But advocates of the law dispute this interpretation and say it contradicts the purpose of the paid leave program.

“My major concern with the regulations is that those who need paid leave the most, our lowest wage workers and our workers in jobs where there is high turnover, might not benefit at all from this program,” says At-large Councilmember Elissa Silverman, one of the law’s authors.

As passed, the law requires that private employers pay a 0.62 percent annual payroll tax for each of their employees for the leave program. (The city started collecting the tax last July.) Anyone who works for part of or a full year is eligible to receive paid leave benefits, depending on how long they have worked and what they earned in that time. But under the city’s regulations, if someone is fired or leaves their job, they won’t have access to any of those leave benefits at all—even the money their former employer already collected as part of the program.

Advocates of the law say this could play out in a few ways. First, if a woman who has been working retail for a year leaves her job late in her pregnancy, she won’t have access to any of the paid leave benefits she accrued while working.

Or if someone works for a small business, they may not have any legal protections from being fired if they get pregnant or otherwise need to take leave. (D.C.’s version of the Family Medical Leave Act, or FMLA, only applies to employers with more than 20 workers. And even when it applies, an employee has to work for a year to benefit from the job protections.) Once they’ve been fired, they lose access to their paid leave benefits under D.C.’s new program.

“That’s the biggest bucket of workers I’m concerned about,” says Silverman. “It’s an uneven playing field.”

Silverman, who wrote a letter last September opposing a first draft of the regulations, says she wanted the paid leave benefits to be “portable”—they would follow workers no matter who they are working for or whether they are between jobs. That’s become an area of increasing interest across the country, especially with the rise of the gig economy and less overall job security and tenure.

But even supporters of portable benefits say they are a ways off, and the D.C. regulations are reasonable and broadly match the way benefits programs are managed across the country.

“I think it’s a sensible compromise because employers have to buy into these plans when they are responsible for funding them,” says Nicole Mason, president of the Institute for Women’s Policy Research. “But I would like states and cities to think about what portable benefits look like for workers. You could lose your job or be between jobs and still need access to those benefits. But that’s not the traditional way we have thought about benefits.”

Last year, Philadelphia implemented a paid leave program for domestic workers that is portable—workers who have met a certain threshold can claim their benefits even if they are between jobs. D.C.’s paid leave law does cover self-employed workers, though they have to pay their own contributions into the city’s fund.

Despite their concerns, advocates say there’s little they can do to change the city’s leave program for now.

“Unfortunately, the path forward is that we have to accept these rules and regulations as written,” says Joanna Blotner, one of the leaders of the campaign for the paid leave law. “We are in an untenable bind in terms of timing. If we make major revisions now or fight this out, the program won’t be able to launch on July 1, and there are real people’s lives at stake.”

Silverman agrees there’s little time to wage a broader fight against the city’s work requirement at this point, but says it could happen once the paid leave program—which is expected to cost $250 million a year—is functioning and officials can see who is taking advantage of it.

“We want to get the program up and running,” she says. “But we want to pay close attention to who’s benefiting.”