This week, coalition of more than 380 major companies proposed a minimum federal paid leave threshold that would exempt them from having to meet more stringent laws in states and cities.

The "safe harbor" proposal is included in a new report from the HR Policy Association, whose members employ 9 percent of American private-sector workers, according to Bloomberg. Members include such well-known names as Marriott International, Procter & Gamble, IBM and General Electric.

The U.S. is the only developed country without a paid maternity leave law. In what Bloomberg called a "preemptive strike" against a federal paid leave law, the report states:

"While large companies are at the forefront of providing generous leave benefits, they are increasingly challenged by a patchwork quilt of varying administrative requirements under state and local mandates.

Companies already providing generous paid leave benefits should have a federal safe harbor from being hampered by the varying requirements of state and local leave mandates."

Paid leave laws have gained traction at the state and local level, with six states (California, New Jersey, Rhode Island, New York, Washington state and the District of Columbia) passing them as well as some cities, according to the National Partnership for Women and Families.

The last presidential election also saw paid family leave become an issue for both major parties, for the first time. Candidate Donald Trump proposed six weeks for new moms only, while in his first official address to Congress, President Trump pledged to "help ensure new parents have paid family leave."

"Because there has been a lack of federal action, you’ve seen communities taking this issue into their own hands," Heather Boushey, Executive Director of the Washington Center for Equitable Growth, told Bloomberg. "If the employers are frustrated that they have different systems, then we should be thinking about what is that basic benefit that we should be providing at the federal level."

Democrat proposals for a federal paid leave law—including the FAMILY Act introduced by Sen. Kristen Gillibrand (D., NY) and Rep. Rosa DeLauro (D., CT)—have languished for years. So far, only the Family Medical Leave Act has passed, in 1993, to allow certain employees to take up to 12 weeks off for a medical issue or to care for a family member. The leave is unpaid and currently covers only about 60 percent of workers.

The HR Policy Association argues that companies don’t need a paid leave law. "While many existing government policies assume employers will only treat their employees fairly if they are required by law to do so, the war for talent negates that assumption," Merck & Co. executive vice president Mirian Graddick-Weir, who chairs the association, wrote in an email to Bloomberg.

And yet, according to an annual benefits survey by the Society for Human Resource Management, only 26 percent of employers offer either fully or partially paid maternity leave.

Notably, the HR Policy Association membership includes a number of 2016 Working Mother 100 Best Companies winners (Procter & Gamble, Johnson & Johnson, IBM, General Electric, General Mills and Accenture, among others). The 32-year-old initiative asks companies to compete on offering the best family-friend policies to employees, including fully paid maternity, paternity and adoption and sick leave.

Last year, the average number of weeks of fully paid maternity leave offered by the winners totaled 9 weeks.

H/t: Bloomberg