Italy’s Parliament is debating a national policy that would allow women to take time off from work due to painful periods. The “menstrual leave” legislation would require companies to give women three paid days off each month and if passed, would make Italy the first western country with such a law.

The proposed legislation is contentious, as critics argue it would lead to fewer women being hired due to increased costs, while proponents say it would greatly benefit females in the workforce.

Bex Baxter, director of the U.K. nonprofit Coexist, has advocated for the policy for more than a year. Coexist implemented a company-wide menstrual leave plan in 2016.

“I have managed many female members of staff over the years and I have seen women at work who are bent over double because of the pain caused by their periods,” Baxter told the Bristol Post in March 2016. “Despite this, they feel they cannot go home because they do not [consider] themselves as unwell. And this is unfair.”

Baxter claimed women would be more productive after taking time off for their period. Twenty percent of women reported menstrual pain severe enough to interfere with everyday life, according to the American Academy of Family Physicians.

However, while Taiwan, South Korea, Indonesia and Japan all have policies allowing time off for women during menstruation, they’re not always taken advantage of due to persistent stigma surrounding menstrual leave.

Opponents of the policy said employers could be motivated to hire men over women if they're forced to allow women more time off. The Italian economy is already dominated by men: only 61 percent of Italian women work as compared with the European average of 72 percent, according to U.K. women’s magazine Grazia.

“If we insist that one group or another has an extra set of costs associated with their employment then we’ll end up seeing the wages of that group fall relative to groups that don’t have these associated costs,” finance expert Tim Worstall wrote for Forbes in 2014. “The provision of paid menstrual leave will act in exactly this manner.”