An equal pay case put forward by female workers is heading for the High Court, where women will allege hundreds of other females are also being significantly underpaid, according to Fairfax Media.
The Court of Appeal made a decision last year that female-dominated industries should receive a rate of pay equal to male-dominated industries.
The decision was made after aged-care worker Kristine Bartlett took legal action against TerraNova Homes and Care, Fairfax Media reports.
Experts feared the case would open a range of related cases, and more than 2500 claims were filed last year with the Employment Relations Authority by aged-care workers claiming low pay based on gender discrimination.
This debate follows information revealing a third of staff working for Parliament now earn six-figure salaries.
The average salary of ministers reached $93,298, up five percent from last year, and the average salary for a New Zealand nurse with three to five years' experience is between $54,000 and $64,000.
Other senior officials are alleged to be earning more than a basic MP's salary of $150,000, although this cannot be confirmed.
Ten-year surgical nurse from Wellington Erin Kennedy told Fairfax Media her working conditions, pay and hours were like a slap in the face.
She said nursing and caregiving is hard physical work and nurses should be recognised for it.
Her colleague Ann Simmons also told Fairfax Media it's not fair that mental healthcare employees get paid minimum wage but have to deal with assault as a common work risk.
In 2014, men earned roughly 10 percent more than women for an hour's work.
The gender pay gap has decreased in the last two decades but last year it increased 7 percent, according to Statistics New Zealand's Quarterly Employment Survey.