All Blacks assistant coach Wayne Smith has come to the defence of the South Island's only education unit for severely disabled children, saying Government funding cuts are "criminal".

Smith, who has a 27-year-old son with cerebral palsy, yesterday attended an end-of-year performance at Addington School by preschool children with disabilities.

The Conductive Education Centre in Addington, which helps children with motor disabilities such as cerebral palsy, will have funding for primary school-age children fall from $114,000 this year to $85,000 next year as a result of Government cuts.

The Government funding will be phased out by 2014.

The centre offers therapy and education for 18 children aged between five and 13.

Smith said children with cerebral palsy would be held back if funding was reduced.

"A lot of these kids have huge needs and it would be a crying shame if the funding for that was reduced," he said.

"They are intellectually brilliant and would do well with a bit of time spent on them. It's just criminal if the funding gets pulled, and lots of these children will not reach their full potential.

"With a place like this, there is expert help and it is a one-stop shop. They have everything they need to learn, and the parents get a lot of support. They are well looked after. They can see what the future might hold for their children."

Parent Jacqui McFall, who has a five-year-old daughter with cerebral palsy at the centre, said the cuts would be "a major backward step".

"The children need the routine and the regular therapy. If they are not pushing their muscles and using them, it shows," she said.

"I saw a major difference in her [after starting at the centre]. When she started here she would just roll on the floor. She is far more socially active and up and about on her walker now.

"I would hate to think where we would be if we were not doing this. It would be an absolute shame. What they do is amazing."

New Zealand Foundation for Conductive Education national co-ordinator Dave Ching said: "The future of these school centres is at risk ... We have a battle on our hands now. It will be a struggle for us over these coming years.

"The real crunch will come over subsequent years as the money is phased out altogether. It gets to a point where the level of funding is no longer enough to employ people."

Conductive education involves physical and educational therapy for children with motor disabilities. There are 10 centres in New Zealand, with about 200 children receiving treatment.

Ministry of Education special education group manger Brian Coffey said funding changes in the 2009 Budget were to ensure spending was "distributed fairly across all students with a similar level of need".

"The priority for Addington School is to ensure that students are well-supported and continue to learn, and the ministry will continue to work with those that provide conductive education to help them continue the programme."