The Resident Doctors Association (NZRDA) said on Thursdayafternoon the 20 DHBs had applied to the Employment Court for an urgent injunction to halt the strike.
DHBs are claiming that because the recently graduated doctors who are members of NZRDA were not employees at the time they were balloted for strike action, they cannot strike even though they will be employees when the strike takes place.
DHBs are also claiming the association's membership ballot on strike action should have been done separately for each group of resident doctors at health boards.
Association national secretary Deborah Powell said: ``The decision of the DHBs to apply for an injunction is unfortunate. If successful, our strike will simply be delayed, not stopped, and is likely to push industrial action into the busy Christmas and New Year period.''
``We had hoped we would have safer rosters agreed to before the graduating class of 2016 started working on the wards. We do not want yet another year of doctors to become worn out and worn down by fatigue.
``It would be nice to think the upcoming strike could be avoided, not by legal action, but by settlement of the contract. All we need is for the DHBs to return to the bargaining table to negotiate a fair deal.''
The strike starting on November 23 is scheduled to be a 48-hour walk-out, on the pattern of the union's strike in October. The last strike led to the postponement of thousands of elective surgeries and outpatient appointments as public hospitals focused on caring for acutely sick or injured people.
On Monday, the DHBs said they were surprised the union had rejected their latest offer, which included a 5% pay rise over three years, and a payment of $200 when working a weekend shift.
DHBs' spokeswoman Julie Patterson said the offer gave the union ``what they have been publicly asking for: a contractual guarantee that no RMO [resident medical officer] would work more than four nights or 10 days in a row''.
The DHBs have said the union expected doctors to be paid for days off resulting from the roster changes.
The union said the DHBs' offer would on average cut members' pay by $5000 to $7000 - even with the $200 payments - because by working fewer hours they would drop into a lower salary band in the collective agreement.
``The DHBs have proposed a system that would see thousands of dollars being deducted from each RMO's salary, far out of proportion to the number or value of rostered days off they may get under safer hours rostering.''
The union was also concerned that the DHBs had not contractually committed to the safer hours.
