Almost 700 medical laboratory workers at private laboratories around the country have gone on strike.
APEX union members employed by Southern Community Laboratories who worked at laboratories around the country, as well as a number of associated collection centres, have stopped work for 24 hours.
The action comes after months of negotiations with employers for better pay rates of those workers, who had also conducted partial strikes over the past month.
The labs covered by the strike are Tlab Gisborne, Taranaki Pathology in New Plymouth and Hāwera, and SCL at Hutt, Kenepuru, Wellington, Nelson, Wairau, Timaru, Christchurch, Ōamaru, Dunedin, Queenstown and Invercargill.
Union national advocate David Munro said it included almost all the medical laboratories in the South Island except for West Coast and Canterbury labs, which were run by the health board.
Previously, Munro said this strike "would see some impact on turnaround times" of Covid-19 testing.
He told RNZ it was not an easy decision.
"Striking in the health sector is something that people who get into the sector don't expect to have to do.
"It's been a very weighty decision for them but I've never seen our members quite so angry, or quite so determined about getting a fair outcome."
Some progress had been made earlier in the week with improved offers for some roles, he said, but many had not seen any change to the previous 2 percent offer.
"Bargaining in the last fortnight has not closed the gap we need. The main problem is still very low offers for the low-paid people.
"In fact, there was no immediate improved pay offer for many of the workers that the employer chose to suspend during our partial strike action last week. The bargaining team was not prepared to settle the agreement, or lift the strike action, in the face of a proposed deal that does not benefit everybody."
Workers were determined to get a settlement that saw them at least earning the Living Wage, Munro said.
However, Southern Community Laboratories chief executive Peter Gootjes said a generous offer was made addressing the key areas raised after two days of bargaining with APEX earlier this week.
"We were confident our offer met their members' needs.
"The offer would see these workers' wages increase by an average of 4 percent each year for the next three years, providing financial certainty over this time."
Dr Gootjes said Covid-19 testing would continue as planned, although delays were likely.
SCL said it was disappointed that 460 of its 1200 staff had gone on strike.
Munro said medical lab workers were registered health professionals who ran laboratories and tested, interpreted and reported laboratory results. They were trained to identify disease and abnormalities through studying blood, tissue and other bodily samples.
He said they were an integral part of the health system and their work was vital to patient treatment.
"Medical Laboratory Workers take on a high level of responsibility, often needing to make important decisions under pressure. Emergencies can occur at any time, day or night, so laboratory workers have to prioritise and use their initiative, often without much back-up.
"If the doctor needs to know the answer, they have to deliver."
Sometimes that meant working through the night providing results while patients fought for their life.
Munro said it was similar to the nursing sector in that there was a big gap between what people were paid in the DHBs and in the private sector.
"I've heard the nurses say the difference is around $7000, while for scientists it's similar and sometimes a higher figure in the private labs, which is below nurses and teachers."
The union says the different between the number on strike varied from its figure of 700 and SCL's figure of 460 for two reasons: It said SCL was using old membership numbers and new members had joined, and it said the 700 included Taranaki Pathology and Tlab in Gisborne which are also on strike today but are not SCL labs.
Yesterday, more than 3000 primary healthcare workers with the Nurses Organisation union stopped working for eight hours, in a bid for equal pay with district health board colleagues.