Junior doctors are striking for the third time this month today, with 290 Blood Service laboratory workers also walking off the job this week.
Te Whatu Ora has accused the unions of knowingly scheduling the strikes at the same time to cause maximum disruption, saying the dual action will compound the impact on patients.
Hundreds of operations were postponed in last week's strike.
That included in the days leading up to the industrial action, to make sure there were fewer people in the ward that might be affected by the strike.
More surgeries were being deferred today.
The blood lab workers started their industrial action yesterday by not working any extra hours, and are going on strike for four hours on Friday.
The PSA - which represented the lab workers - said the Blood Service and Te Whatu Ora were keeping a close eye on blood stocks and some staff would return to work if blood was needed for life-preserving reasons.
There was enough on hand for acute operations that could not be deferred, it said.
The four-hour strike was part of wider action that included not working extra hours and not processing AHF plasma, which was sent to Australia for commercial processing rather than directly to hospitals.
Next week the workers would strike for 24 hours if the dispute had not been resolved.
They want the Blood Service to pay them the same as their hospital counterparts, and plan to strike for longer next week.
The junior doctors are part of the Resident Doctors Association which represents about half of all junior doctors, more than 2500 of them.
President James Anderson said Te Whatu Ora has barely moved on its demands for fair pay and for an end to back-to-back 15 hour weekend shifts.
It was also trying to "claw back" a 50 year old clause that meant doctors got $5000 when they passed their first exam, he said.
Te Whatu Ora chief people officer Andrew Slater said he was frustrated and disappointed the doctors were was still going ahead with the strike despite the Employment Relations Authority recommending they paused during facilitation.
The pay increase offer - between 3 and 29 percent - was fair, he said.
Hospitals would remain open and patients should turn up to appointment unless contacted, he said.
RNZ
