Supporters of paid family leave at D.C. city hall in 2015. (Jabin Botsford/The Washington Post)

The District’s elected leaders spent the final months of 2016 debating and adopting a law that guaranteed eight weeks of paid leave to new parents who work in the nation’s capital.

Now it seems they are preparing to spend the final months of 2017 arguing over how, and whether, that landmark legislation needs to be overhauled.

A D.C. Council committee held a hearing Tuesday on suggested changes to the law, which, in addition to parental leave, guarantees six weeks of paid time off to care for ailing relatives and two weeks of personal sick time. The requirements apply to private-sector workers in the District, but not federal workers or employees of the city government.

Proponents of the various amendments say they would preserve the same amount of time off for workers while lightening the tax burden the current law places on businesses and avoiding the creation of a large new District bureaucracy to oversee the benefits.

But advocates for the original law passed by the council last December say it could be fatally weakened by the tweaks under review, such as a provision that would allow large businesses that already grant their employees the prescribed amounts of paid leave to opt out of the city’s program and not support it through taxes.

David Grosso (I-At Large), one of the progressive council members who introduced the original legislation last year, said the proposed amendments were “a manufactured solution to a made-up problem.”

A spokeswoman for Mayor Muriel E. Bowser (D), who opposed the current law but did not veto it, declined to say Thursday whether the mayor supports any of the changes being debated by the council.

The District’s current program would increase employers’ payroll taxes by 0.62 percent, using the resulting revenue — projected to be about $250 million annually — to create a public insurance pool that would pay workers during their time off.

The city would reimburse employees for 90 percent of their first $900 in weekly pay and 50 percent of their remaining weekly pay, with a cap of $1,000 per week. Those benefits are supposed to be available under the existing law beginning in 2020.

The proposed amendments on the table would ostensibly maintain benefits at those levels but change who pays for them and how.

Some would reduce or eliminate the tax on businesses while requiring them to provide paid-leave benefits on their own — an “employer mandate” that contrasts with the current system in which reimbursements for time off will be paid directly by the city.

The employer mandate has been championed by business groups and would particularly benefit large organizations that already provide some form of paid time off and don’t want to be saddled with an additional tax. But critics say it would unfairly burden small businesses and could invite abuse by companies that try to evade the mandate.

Pronita Gupta of the Center for Law and Social Policy said in her testimony that the District’s new publicly administered benefit program, in contrast to the employer mandate, “makes it harder for low-road employers to try to skip out on contributing their fair share.”

Council member Mary M. Cheh (D-Ward 3) — who both voted for the current paid-leave law and drafted or co-sponsored several of the changes under consideration — said smaller companies could still be eligible for some form of insurance policy that paid their workers’ benefits — either through a private company or through the District government.

Cheh also said she favors shifting part of the cost of the benefits to employees.

Other states such as California and Rhode Island use worker contributions to fund their paid-leave programs, but District officials avoided that approach because the city is barred by federal law from taxing those who work in the District but live outside the city.

Cheh said the prohibition could be avoided by setting up the employee contribution as a fee rather than a tax, though she acknowledged such an approach could be challenged in court.