It comes as the disability support service struggles to meet growing demand for early-intervention physiotherapy, speech therapy and occupational therapy not covered under the National Disability Insurance Scheme.

Fund-raising manager Danielle Blewett said the appeal had so far received 100 donations amounting to $15,000, compared with 300 donations at the same time last year.

The fund-raising target is $70,000.

Ms Blewett attributed the drop to the federal budget, saying St Giles typically received most donations from working and single-parent families likely to be affected by cuts and co-payments.

"Our donors are historically large numbers of people making small, affordable donations of, say, $10 to $20," Ms Blewett said.

"They have almost vanished."

Ms Blewett said the decline in community donations came as funding shortfalls forced St Giles to slow its waiting lists and turn away new speech pathology referrals.

She said this was because Commonwealth and state funding for early intervention services had not increased in line with demand, and the services were not covered by the NDIS.

"At the moment St Giles is carrying the shortfall from its reserves," Ms Blewett said.

"The shortfall this year is $1 million."

Ms Blewett said it wasn't clear who would fund early intervention when the NDIS - currently under trial - was fully rolled out.

"The Commonwealth and state government have identified early intervention therapies as a priority to get kids ready for school," Ms Blewett said.

"But no one wants to pay for them full-term because it's really expensive.

"One of them is going to have to put their hand up."

To donate, visit www.stgiles.org.au