TORONTO -- A new study shows nearly half of Ontario's elementary school and roughly 40 per cent of high school principals have recommended students with special education needs not attend school the full day.

The report released Monday by the non-profit People For Education is based on a survey of 1,349 elementary and secondary school principals from all 72 of the province's school boards. It was administered in the fall.

The group says it added a question about asking special-needs students to stay home at least part of the day after fielding numerous calls from concerned parents.

The Education Act requires students between the ages of six and 18 to attend school unless excused due to illness or "other unavoidable cause."

But principals have a legal duty not to admit anyone whose presence they believe would have a negative impact on students' physical or mental well-being.

The report says principals sometimes ask students with special needs to stay home because the support they need is temporarily unavailable, or to ease the transition during a major change.

In extreme cases, it says, students may be asked to leave school most or all of the day if there is no way to provide the care they need or ensure their safety.

"We have an autism spectrum disorder student at the severe end of the spectrum. He is unable to toilet himself, and was not provided with a special needs assistant as requested. He was too disruptive to be kept in the building beyond one hour, two days a week," one Toronto elementary school principal wrote.

"For quite a few (principals), it seems that it comes down to a feeling that there's just not enough support at school," says Annie Kidder, the organization's executive director.

"So if there isn't an educational assistant in place, for instance, all day, it's hard then to feel that the student will be supported enough to stay at school."

In some cases, the comments suggest the decision "may relate less to practical constraints and more to a principal's feeling that a student may not be capable of dealing with a full day of school," the report says.

The document adds that resources remain a constant problem when it comes to teaching children with special education needs.

It says Ontario elementary schools have, on average, one special education teacher for every 37 students with needs, a ratio that has stayed largely unchanged in the past four years. High schools, by comparison, have one for every 74 students.

Forty-four per cent of elementary schools and 33 per cent of high schools report that not all students have access to the assistive technology prescribed by their psychological assessments or education plans.

Getting a timely assessment is also a struggle in many schools, the report says.

Only 39 per cent of elementary and 32 per cent of high schools have regular access to a psychologist for an average of 11 and 16 hours per month, respectively, the document says. And a single assessment can take up to 10 hours.

Twelve per cent of schools report having no access to a psychologist, according to the study.

The province is changing how it distributes funding for special education, which accounts for $2.72 billion of this year's budget.

The changes aim to shift funds where they are most needed, which means some school boards will receive less money than they did in previous years.