Tensions between district health boards and radiographers mounted on Tuesday, with DHBs withdrawing a pay offer to the group and radiographers threatening more strikes in return.
Staff who do x-rays, images and scans have been striking for months over a lack of progress in pay talks.
DHBs said on Tuesday that after 14 months of negotiations, nearly 600 strike notices and five pay offers, they are calling it quits with the Apex union, which represents radiographers.
The DHBs say they offered radiographers a 1% rise in April and another 1% in October, but the union has continued to make extra demands that would push the cost of settlement above what DHBs can afford.
The radiographers say there is no dispute over pay, but they are insisting on conditions that are important to them.
These include time in lieu for professional development activities done at weekends, and pay parity for sonographers.