Childcare workers say creche fees will increase until the Government provides 100% of their costs.
The warning follows a threat by the Children's Minister Katherine Zappone to cut new subsidies for those caught hiking their prices.
Minister Zappone claims her budget will be reduced if the system looks like poor value for money, and said she may cut the childcare subsidy to creches who are hiking their fees.
She warned providers against making "rash decisions" when setting their fees.
However, Teresa Heeney from Early Childhood Ireland said creches badly needed more government money.
She said: "Fees have to increase until the Government is providing 100% of the cost of provsion of an early-years service - including staff costs, building, insurance and salary increases.
"Until they're covering all of those, these independent ernterprises have to be allowed to sustain their services."