Some of Northern Ireland's most vulnerable children with special needs have been neglected and short-changed by the system, a teaching union has claimed.
Half of teachers surveyed believed they were under-resourced and many felt the situation was becoming worse.
They claimed better pupil support and smaller class sizes were needed to arrest the decline.
Avril Hall Callaghan, general secretary of the Ulster Teachers' Union (UTU), said: "This paints a very worrying picture about the state of support for our most vulnerable children - it reveals a deteriorating trail of under-resourcing and neglect.
"How can parents have confidence in a resource-starved system with which teachers are struggling to work?"
The report was prepared by the UTU and the Irish National Teachers' Organisation (INTO) and focused on the state of the special educational needs sector, which included pupils with learning difficulties and needing extra forms of support.
More than 350 teachers in mainstream and dedicated special needs schools were surveyed during the first two months of this year.
The vulnerable young people can be taught in dedicated schools or as part of the regular education system.
A third of teachers felt the situation was becoming worse, half believed they were under-resourced while a third claimed inadequate training was given.
A third said they lacked adequate access to an educational psychology service and a quarter believed support from advisers was unhelpful. Teachers also said the system was not keeping pace with technology.
"Better pupil support and smaller class sizes would do more for the children at this stage than increased technology availability," they said.
Mainstream schools increasingly have to cater for children with special needs. A total of 71,581 young people are being taught, the vast majority in regular schools.
Ms Hall Callaghan added: "Of course this inclusivity is to be welcomed, but it must not be at a cost - whether to the special educational needs child or the other pupils."
While special schools receive extra funding once a child's special needs are recognised by the local education board, the trade union leader said mainstream schools do not receive the same financial "fillip" to deliver the extra support necessary.
"These schools are forced to stretch their existing budgets in an effort to give every child - of whatever ability - the best possible chance," she said.
"Without adequate funding special needs children in mainstream schools risk being let down by the system and missing out on vital support which could enable them to fulfil their potential.
"They are being short-changed."