Parents may have to pay higher fees for less service when childcare centres reopen.
Early Childhood Ireland will tell the Oireachtas COVID-19 committee today that more state funding is needed to avoid that.
It will say the coronavirus crisis has worsened the sector's crisis.
Speaking ahead of today's hearing, Teresa Heeney - chief executive of Early Childhood Ireland - said parents can't make up the funding shortfall.
She said: "What we're going to need in a very short period of time is clarity for the 2,000 or so operators of pre-school facilities who run the free pre-school programme on behalf of the Government.
"Them and all of the parents in those services are going to need to know what level of reopening grants, capital grants, wage subsidies... what is going to be available.
"Parents can't make up the shortfall."
Ms Heeney noted it's still uncertain how many providers will be able to reopen next Monday and how many parents will return their children to childcare.
She said the sectors needs "vastly increased" levels of investment to ensure it is secure in the long-term.
Other groups set to appear before the committee today include SIPTU.
The union said they'll highlight first-hand accounts of difficulties faced by frontline health workers in finding childcare since the start of the pandemic.
