Taoiseach Micheal Martin has urged medical scientists to call off their strike and resume pay talks.
But the Medical Laboratory Scientists Association urged him to intervene in their long-running row with the HSE.
They are essential cogs in the service and carry out vital procedures including Covid and blood tests.
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There are more than 2,000 of them in the health service and their demands include better pay and career progression prospects.
After staff joined pickets outside hospitals yesterday, Mr Martin urged them to return to the negotiating table.
He told TDs: “I take the opportunity to recognise the hugely important work, the vital work carried out by medical scientists and their role in respect of the functioning of our health service.
“They are dedicated. They are professional and are very, very committed and have been for many many years, particularly during the pandemic.
“I believe the parties should continue at the Workplace Relations Commission.
“Ultimately, pay disagreements of this kind have to be resolved through the existing labour and industrial relations mechanisms. That is the most effective way to do this.”
Earlier, Socialist/People Before Profit TD Paul Murphy told the Dail the public are on the scientists’ side and he called on the Taoiseach to back them too. He said: “The public support for them and the support from patients has been quite overwhelming.
“These are the hidden heroes of our health service.
“They are the people who process test samples for Covid, blood tests, who test urine and stool samples.
“They’ve been under intense pressure during the Covid crisis and many are now suffering burnout as a result of problems with recruitment and retention which means that one in five medical scientist places are currently unfilled.
“Their work is absolutely vital for modern medical treatment.”
Thousands of appointments were cancelled in hospitals because of the strike and the HSE warned of huge delays in A&Es.
Medical scientist Clara O’Mara joined the picket at University Hospital Limerick.
She told the Irish Mirror that they have seen “tremendous” public support.
Ms O’Mara said: “We are looking for pay parity with biomedical chemists.
“We were told by the HSE that we do the same work. We were first told this 20 years ago, so why can’t we get the same pay?
“We’re just looking for a fair deal and I think the public recognise this.
“We have been getting beeping of horns and salutes from the public, which makes a difference because we are not doing this lightly. We’d prefer to be at work.”
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