About 3000 health care workers are going on strike in Auckland.
The workers at three Auckland District Health Boards are protesting a plan to reduce weekend penal rates for new staff and increase patient services.
Their union says this will stretch new staff when current staff are already "at breaking point due to systemic underfunding and understaffing".
Striking staff work in more than 40 different roles including physiotherapists, dieticians and laboratory technicians.
"The DHBs plan to stretch their staff further in an attempt to provide seven days of services to patients, but we're working past our limits just trying to cover five days right now," said Public Service Association representative Andy Colwell, a DHB mental health worker.
"We are already missing breaks and working overtime, often for free, to try to protect our patients from the dangerous effects of the government's health cuts."
Auckland DHBs spokeswoman Julie Patterson says currently staff are paid double-time for weekend work, and the DHBs want to pay new staff time and a half - which is in line with most DHBs nationwide.
"The change to weekend penal rates for staff who are employed in the future will support our ability to expand the provision of allied services to meet patient demand," she said.
The DHBs are confident they can minimise the impact of the strike action on patients.
They will only return to the bargaining table if the strike action is cancelled and no further action is taken, Ms Patterson said.
Waitemata DHB, Tuesday 8-10am
- North Shore Hospital
- Waitakere Hospital
- Point Chevalier
Auckland DHB, Wednesday 8-10am
- Auckland Hospital
- Greenlane Hospital
Counties Manukau DHB, Thursday 8-10am
- Middlemore Hospital