Bathgate Park School principal Katrina Robertson said there was already a high demand on learning and support services and any reduction to them would be problematic for schools and their pupils.
This follows the ministry’s announcement last Wednesday of a proposal to cut 565 jobs.
About 100 were regional and frontline roles, including 38 roles for supporting pupils with disabilities and learning support needs.
A breakdown of how the proposed cuts would affect Otago and other regions was not provided.
Mrs Robertson said the wait times to access some services could be increased.
"Some more specialised personnel are already thinly stretched with the number of children they can take, so this will mean it is less likely that all children needing support can be picked up."
Ministry-funded services such as speech therapists and clinical psychologists supported pupils to reach their full potential in a timely manner.
"Some children will struggle to be able to reach their full potential. Their ability to self-regulate, communicate and foster a positive relationship and attitude towards learning may be affected.
"For some of the students with higher levels of need, it will potentially affect their ability to access their curriculum level."
Without the support it would be hard reaching targets set by the government and some children would fall further behind.
"Instead of putting the support in now when it can do the most good, it may be a case of the ambulance at the bottom of the cliff later on in their life, when it is harder to make a difference."
Bathgate Park was not in a financial position to continue offering the services independent of ministry funding, Ms Robertson said.
Dunedin staff from the ministry were invaluable for the support they offered.
"As a principal, in a job that already has a number of challenges and stresses, knowing we have this support is a necessity.
"To reduce this is going to have a huge impact on many people and will have flow-on consequences."