In 1897 the first conference of the National Council of Women tackled pay inequality.
It introduced a policy that "in all cases where men and women are engaged in the same work, either in the employment of government or of private individuals equal wage should be paid for equal work".
Nearly 125 years later, the organisation is still battling for it.
"So here we are in 2021 and we're not there yet," says the council's Carol Beaumont, who has been campaigning for equal pay for four decades.
The battle for equal pay has hit false starts and celebrated milestones over the decades but still women are paid on average nine percent less than men when it comes to the median hourly rate.
The gap stretches to more than 27 percent when comparing the pay of a pakeha male and a Pasifika woman.
The Detail today looks at what has happened to pay gaps since the Equal Pay Act of 1972, which requires "that men and women doing work requiring the same, or substantially similar, skill, effort, responsibility and working conditions are paid the same".
Today marks the start of the act's 50th year with a new campaign, called Mind the Gap, backed by 35 organisations including unions, women's groups, and BusinessNZ .
It is calling on large employers to measure their pay gaps and make them public on a registry to be launched next year.
But it also believes that to close the pay gaps, mandatory pay gap reporting is required as it is in Australia, the UK and other countries.
The pay gap is described as the difference in earnings between two groups of people - between men and women, or different ethnicities.
"It's not just a number and it’s not just about being unfair and discriminatory," says Beaumont. "It actually has a real impact on people's lives; for many it is about living in poverty and that is particularly true where women are the main breadwinners."
Even for the same job, despite the Equal Pay Act of 1972, people are still paid unequally. Factors include workplace discrimination and unwillingness of employers to be up front about what workers are paid.
Beaumont also cites "occupational segregation", where women are concentrated in jobs that have been undervalued such as care work.
"That's the pay equity piece and we've had amendments to the Equal Pay Act so people can start to deal with those pay equity cases. These are the nurses, the midwives, librarians, clerical workers."
Only four companies in Aotearoa disclose their pay gap. One, Genesis Energy, has a gender pay gap at 35 percent.
"At face value that's a huge gap," says chief executive Marc England.
But on "like for like roles" the gap is very low, meaning for men and women in the same or similar jobs there is a 1.7 percent difference in pay.
England is co-chair of Champions for Change, a group of CEOs and chairs of 40 large organisations across New Zealand leading the charge on diversity in the workplace.
He reckons fear of backlash is behind a lot of CEOs' decisions not to disclose their pay gap.
"I could tell by the tone of your voice when I said our total gender gap is 35 percent you were a little bit shocked,” he tells Sharon Brettkelly.
"And I think there's a bit of fear in reporting it because there are some big numbers out there, particularly in businesses like ours where you've got a disparity between technical qualifications and maybe more manual work, more part time work, which might have attracted more women in the past."
He's hoping that will change with the launch today of Mind The Gap, a campaign urging companies to publicly report their pay gaps, gender and ethnicity.
"We need more companies to disclose their gap because only when you start disclosing it you start focussing on it, and it’s like everything in business - if you report it, you act on it; the more companies report it, the more we get a deeper understanding of the problems that are causing it."