Auckland District Health Board says it is unacceptable that industrial action by laboratory workers at Auckland hospital is disrupting the standard of care that patients should expect to receive.
About 1000 medical laboratory staff around the country are campaigning for pay rises.
There are nearly 400 laboratory workers at the three DHBs in Auckland and most are understood to be refusing to carry out some duties as part of their industrial action.
Chief Medical Officer Margaret Wilsher says the action is increasingly frustrating surgical staff and clinicians, who are having to delay patient treatments.
Dr Wilsher says patient tolerance has run out with some being sent home to wait for the dispute to resolve.