Hospital sonographers - who do ultrasound scans - have begun issuing strike notices as they try to win a long-running pay battle.
Their union Apex sent the first notice to the Capital and Coast DHB earlier this week saying they would walk off the job for three days from Wednesday, 12 November.
All six sonographers from Dunedin and Invercargill notified the Southern DHB they planned to strike immediately after the Wellington action for five days.
Invercargill sonographer Bernadette Gourley said they had been negotiating with the DHBs for a national pay parity deal for 15 months and would not wait any more.
"Sonographers have been pushed to their absolute limits of their patience, their endurance and energy and this is the only course of action that is left to them."
The union said patients were waiting up to a year for an ultrasound because of sonographer shortages from South Auckland south.