Junior doctors are warning they won't back down in their fight to keep their current contracts.
It comes as DHBs hit back at the NZ Resident Doctors' Association's claims about discussions at Thursday's mediation.
The NZRDA's David Munro says they're in a campaign they need to win, as they launch their third strike.
DHBs insist there's nothing in their proposal that would impact safe working.
"There is nothing in our proposal that would impact the safe working of the [doctors]," said spokesperson Peter Bramley.
"DHBs are disappointed a third strike has been notified instead of working toward a solution in the interests of patient care."
Mr Munro says they're miserable about having to give the latest strike notice.
"That's not to say that the determination isn't there - it's still there, and it will continue to be there until the DHBs make some sort of amendment in their position."
Failure to do so will "lead to an outcome where people are working unsafe rosters", he says.
More strikes beyond the third aren't being ruled out too.
Junior doctors say they have to work 16-hour shifts, sometimes 12 days in a row.