Medical scientists have served notice of industrial action in a dispute over pay and career development issues.
The Medical Laboratory Scientists Association (MLSA), the trade union representing medical scientists, says its members will go on strike between 8am and 8pm on Wednesday, 30 March.
The union has warned that if no progress is made, a further two days of action are planned for 5 April and 7 April.
The MLSA says the action follows an unsuccessful period of talks within the 'Building Momentum' public sector agreement.
The union is seeking pay parity with scientific colleagues who work in biochemistry laboratories.
"Medical Scientists carry out identical work, with the same responsibilities, and yet are paid on average 8% less, with fewer promotional and career development opportunities and less support for training and education," according to MLSA General Secretary Terry Casey.
"There remains an ongoing significant national shortage of medical scientists across the public health service. This is in no small part due to inferior pay and conditions, poor career structure and limited promotional opportunities," Mr Casey added.
Medical scientists carry out critical diagnostic testing of patient samples.
The Medical Laboratory Scientists Association represents more than 1,800 medical scientists employed in public voluntary hospitals, HSE hospitals, private hospitals and the Irish Blood Transfusion Service.
The union says its door remains open to any meaningful approach or solution which could avert the action.