Two thirds of Irish charities have seen a drop in funding of between 11 and 25% since 2009, according to a new report by umbrella group The Wheel.
Speaking on RTÉ's Morning Edition, Ivan Cooper, the head of advocacy at The Wheel, said that this fall in funding has had a "significant effect on the services that can be provided by the charities."
Mr Cooper acknowledged that a regulator will bring some transparency to the charity sector, but said discussion is needed on how public services are provided here.
He added that controversies such as that surrounding Rehab and the Central Remedial Clinic have had a negative impact on charities.
He said that for over half of the two thirds that are reporting a fall in funding of between 11 and 25%, funding has continued to decline this year.
Mr Cooper said The Wheel has seen an increase in the uptake of governance training from individuals and charities in recent months.
He said there has been a cultural shift within the charity sector and trustees are now showing a better understanding of their roles as custodians of public funds.
He added that it is imperative that public trust and confidence is maintained through the openness and accountability of Irish charities.
There are over 8,500 charities operating in Ireland.
Mr Cooper said this equates to fewer charities per capita when compared with England, Scotland and Wales, and is a demonstration of how Irish charities are addressing gaps in public services.
Mr Cooper urged all charities to publish their accounts online and larger charities to publish the salaries of their CEOs to ensure total transparency in the sector.