The Service and Food Workers' Union has taken caregiver Kristine Bartlett's case to the Auckland Employment Court, arguing her $14.32 hourly pay breaches the Equal Pay Act.
It comes amid legal action challenging the right of home-care workers to be paid for time spent travelling between jobs, and a case under appeal involving KiwiSaver employer contributions and whether they can be deducted from low-wage workers.
And in 2011, carers won the right to be paid the minimum wage for sleep-overs. Prof Geddis said the union needed to demonstrate in its case in Auckland that workers in the female-dominated care sector had similar levels of responsibility to higher-paid jobs.
The union sought a broad interpretation of the Equal Pay Act to address ''structural discrimination'' between sectors, Prof Geddis said.
A successful case would set a precedent, potentially forcing occupational groups to raise pay rates.
Whatever the verdict, the case was likely to be appealed to the High Court and beyond, as it had significant implications for the whole labour market, Prof Geddis said.
''If Ms Bartlett wins her case, it will create a precedent whereby the union can say to employers: 'Under the legislation, the court says the rates of pay you're paying are illegal'.''
The case could act as an ''indirect'' challenge to private-sector outsourcing, which had driven wages down.
''[Low wages are] the obvious outcome of the privatisation policy that's been applied in this area.''
Litigation over equity issues was an alternative to striking for higher pay, which for low-paid workers was often not an effective option.
''It will be a co-ordinated litigation strategy [by unions]. They're trying to work out [how they] can use the legal system to achieve [their] end, given that other ways of doing it may not be as successful.''
The three-day hearing this week concluded on Wednesday. A finding is expected to take some time.
