A new café in Melbourne, Australia is charging men an 18 percent premium that staff are calling "the man tax" to "reflect the gender pay gap."

Café Handsome Her opened on Thursday and is hoping to highlight the issue of gender equity with its business, CNN reports. Gender equity is different than gender equality because the latter treats everyone the same and seeks to promote fairness while the former involves giving everyone what they need in an effort to "level the playing field."

In the name of gender equity, the café is imposing an extra cost on purchases that men make.

A chalkboard outside of the café explains the policy:

"Handsome Her is a space by women, for women. House Rules: Rule #1: Women have priority seating. Rule #2: Men will be charged an 18% premium to reflect the gender pay gap (2016) which is donated to a women's service. Rule #3: Respect goes both ways."

"Well, it's been a hectic couple of days. Who would have thought that one little chalkboard would cause such a stir?" a post on the Handsome Her Facebook page reads.

Handsome Her's manager, Belle Ngien, said that donations are collected one week every month and given to women's charities. The first charity is Elizabeth Morgan House Aboriginal Women's Services, which focuses on family violence against women and children.

"All we really wanted was to raise awareness and start conversations about the gender gap," Ngien told CNN.

CNN noted that a government report found that in Australia men earn on average 17.7 percent more than women for full-time work. The outlet added that "the difference is roughly the same in the United States."

It did not take long for people on social media to express their views on the café's controversial policy, which critics say is discrimination based on one's sex.

Discriminating against individuals for the group they belong to – race, gender, sexual orientation, ethnicity – is morally and legally wrong — Danny McLean (@Dan___McLean) August 7, 2017

I'll give you 6 months, tops. SJW and sexist women voting with their empty wallets, what could possibly go wrong ? — JoeVSta (@JoeVSta) August 4, 2017

Enjoy going out of business. Discrimination on the basis of sex is a great way to chase away half your possible customer base. Morons. — Osiir (@Osiir11) August 7, 2017

Other worries arose from Twitter users who questioned whether trans people would be charged the 18 percent tax.

My son is in very early transition

Will she be surcharged? — Daddy'sDaughterTime (@MeetN2vegg) August 6, 2017

Ngien responded to the criticism by saying that "men have their own spaces that we're not allowed in to, so why not have that space for women?"

The manager said that no one has declined to pay the extra 18 percent for the six days that the café has been open so far. Ngien even said that some donated more, arguing that 18 percent is not much of an extra cost.

"Eighteen percent is actually not a lot," Ngien said. "Our coffee is $4.00 and 18 percent of that is 72 cents."

Owner Alex O'Brien said in a Facebook post that people—including men—have traveled to support the cause.

"We've had men travel across town to visit us and pay ‘the man tax' and throw some extra in the donation jar," O'Brien wrote. "Guys, you're pretty neat."

UPDATE: 1:00 P.M.: This article's headline originally said "gender tax" but it was actually called a "man tax."