While recent research shows that the gender wage gap is getting worse for women under 40, New Jersey took a major step forward on Tuesday by enacting the nation's strongest equal pay legislation.

"At a time when women's rights are under attack in most of our country, New Jersey has become an exciting exception," noted Deb Huber, president of the National Organization for Women of New Jersey (NOW-NJ). "This pay equity bill has many provisions which set a new high bar for state laws to ban discrimination in the workplace."

S104 (pdf), which takes effect July 1, bars employers from paying women and other "protected classes"—such as people of color—lower wages than white men for "substantially similar work." Differences in compensations are now only permissible when based on a merit system, a seniority system, or if an employer can demonstrate that a worker deserves to receive a higher rate based upon quantity or quality of production, training, education, or experience.

Employers cannot lower the wages of higher paid employees to close gender wage gaps, and those to found in violation of the law could be ordered by a state court to pay up to six years in lost wages, three times what's promised under federal law.

The legislation comes as the Pew Research Center reports that last year, American women earned 82 percent of what men were paid. In 2016, the U.S. Census Bureau found that women earned only 80 percent of what men made.

"Women in every state and in nearly every occupation experience the gender pay gap," state Assemblywoman Pamela Lampitt (D-Camden), a sponsor of the bill, told NJ.com. "Though the gap is gradually closing, it's doing so far too slowly and many women still do not receive commensurate compensation for their work. Stricter measures to ensure parity in the workplace are clearly needed."

The measure passed the state Senate unanimously and was only opposed in the Assembly by two Republicans. The governor signed it into law on Tuesday. Equal pay advocate Lily Ledbetter was among those who spoke at the signing ceremony.

"The state's new Governor, Phil Murphy, highlighted women's rights in his campaign," Huber pointed out, "and the first bill that he signed was to restore funding for women's healthcare facilities, including Planned Parenthood."

Murphy, a Democrat, assumed office in January. His Republican predecessor, Chris Christie, had slashed the state's family planning funding and repeatedly vetoed the equal pay measure.

"From our first day in Trenton, we acted swiftly to support equal pay for women in the workplace and begin closing the gender wage gap," Murphy said Tuesday. "Today, we are sending a beacon far and wide to women across the Garden State and in America—the only factors to determine a worker's wages should be intelligence, experience,and capacity to do the job."

Ahead of the ceremony, the governor tweeted that through signing the bill, he hoped to honor his mother, "and millions of hardworking women like her."