Tens of thousands of other caregivers in the disability and homecare sectors, supermarket checkout operators and other retail staff, teacher-aides and other school support workers, hotel housekeepers, restaurant staff, bank tellers, librarians and social workers could all potentially use the case as a precedent for court actions.
In its decision released today, the Supreme Court dismissed TerraNova's application for leave to appeal, saying that the application was premature because the Court of Appeal had yet to consider the next stage of proceedings - the setting of principles under Section 9 of the Equal Pay Act.
"We therefore consider that the application for leave to appeal should be dismissed. However, this is without prejudice to [TerraNova's] ability to challenge any of the findings of the Court of Appeal on the preliminary questions it dealt with in any subsequent appeal before this Court," the Supreme Court decision said.
A similar case in Australia in 2012 ordered 4000 mainly non-profit agencies to raise the wages of 150,000 mainly female disability and homecare workers by between 19 and 41 per cent over eight years.
Aged Care Association chief executive Martin Taylor has previously estimated the Bartlett case could cost $120 million to $140 million a year for the 33,000 workers in residential aged care alone.
The Public Service Association said the case would now return to the Employment Court where principles would be determined that would set the pay equity rate for Ms Bartlett's job in aged care.
"Kristine Bartlett's strong action in taking this case has helped to put pay equity on the agenda, and will impact on women across many sectors, not just in aged care," PSA national secretary Erin Polaczuk said.
"More needs to be done and we hope the Employment Court process continues to produce such positive outcomes. It is not acceptable that so many of New Zealand's workers are paid less because the work they do is seen as women's work."