Childcare workers will seek higher pay before taking part in any new scheme to look after the children of front-line staff during the coronavirus pandemic.
A Siptu official said workers on "poverty" wages should not be asked to take part without earning at least a living wage of €12.30 an hour.
Siptu head of organising and campaigns Darragh O'Connor said the scheme must be "genuinely voluntary" and fully adhere with HSE advice to limit the spread of infection.
It is understood that a scheme proposed by Children and Youth Affairs Minister Katherine Zappone would mean staff taking part would receive a premium payment.
A department spokesperson said "the provision of early learning and care and school- age childcare services for front-line health staff is a matter that is being actively considered at present by the Department of Children and Youth Affairs and the Department of Health and HSE".
Siptu official Mr O'Connor said some early years educators have underlying health conditions or are living with elderly parents.
"No childcare scheme can be based on poverty wages," he said. "Appropriate rates of pay should be agreed with Siptu representatives and the department for this vital work."
The scheme is being considered as laid-off staff in the sector are set to get their wages fully funded by the State up to €350 a week under a new rescue package secured by the minister for the industry.
In return, childcare providers will be asked to stop charging parents.
Thousands of parents have been caring for their children at home while also paying crèche fees to ensure they still have a place when they reopen.
Childcare schemes to assist front-line and emergency staff have been rolled out in other countries to enable them to work during the pandemic.
Workers including doctors, paramedics, firefighters, police and nurses have been able to access emergency childcare in Toronto and Ontario in Canada.
Childcare centres that had been ordered to close were later exempted to facilitate workers preparing for a surge in coronavirus cases. Some of the centres are operating round the clock.