Ten staff who worked for decades in Middlemore Hospital's kitchen before the Compass Group took over the operation say they are owed hundreds of thousands of dollars by the company.
Compass is one of the world's biggest catering companies, and supplies nearly half of all public hospital meals in New Zealand.
The company has been the focus of protests in recent months about the quality of the food that it has supplied to hospitals in Otago and Southland.
Last July, Compass switched from cooking food in-house to pre-packaged meals and made 14 Middlemore kitchen staff redundant in the process.
Ten of those workers, many of whom had been working there since the 1970s, took voluntary redundancy on the basis of retirement.
Under their union's collective agreement, because they had worked there for so long, they were owed gratuity pay - a sort of thank-you payment for long service, E Tū said.
The women were owed roughly $30,000 each, the union said.
Industry co-ordinator Jill Ovens said the women got their redundancy pay, but 10 of them were still waiting for retirement gratuities.
In a statement, Compass human resources director Marion Hetches confirmed the two sides were still discussing the payment and acknowledged the process was taking longer than it should.
The company hoped to come to a deal over the "coming weeks", she said.
Ms Ovens said Compass rejected the union's claim last year, and so it took legal action. There was mediation in April, and the union said it expected Compass' lawyers to come back with an offer within a week.
"Here we are more than two months later and their lawyer told us this week they're still working through the issues.
"Enough is enough. These women spent their whole working life cooking food for the patients at Middlemore and they deserve to be paid their full entitlement," Ms Ovens said.
Counties Manukau District Health Board, which gave Compass the catering contract, said the payment was a matter between Compass and the union.