TORONTO - Ontario's self-described "Education Premier'' is doing little to clear the growing backlog of autistic children waiting for a crucial but costly therapy, critics charged Tuesday.

The wait list of autistic children who are eligible to receive intensive behavioural intervention therapy, or IBI, reached 1,148 on March 31, up from 985 last year.

More than 1,400 children were receiving IBI services as of March 31, according to newly released government figures.

But the long waits have forced many parents to drain their savings and go into debt to pay for the therapy the province has promised to provide, said NDP critic Andrea Horwath.

The government is moving at such a "glacial pace'' to get kids off the waiting list that many parents are worried their children won't get the service they need in time, she added.

"They feel that their children are rotting on the vine,'' Horwath said.

"Those are the words that more than one group of parents used at a town hall meeting about a month ago. That's a frightening and horrifying thing for a parent to have to admit.''

The wait list is getting longer because the province is putting more money into providing therapy for autistic children, said Premier Dalton McGuinty.

"We've tripled the funding in the last four years, we've doubled the number of children who are being served, and we're bringing therapy into the classroom for the first time,'' he said.

"So I think we're making some real progress, but obviously there's more to be done.''

Teachers and support workers are currently being trained to provide another kind of therapy, called applied behavioural analysis, in schools, said Education Minister Kathleen Wynne.

Some schools already have therapists to provide the more intensive IBI therapy, but not in regular classrooms as the one-on-one treatments work better in a separate space, she said.

Children and Youth Services Minister Deb Matthews said the province has moved "aggressively'' to improve services, such as funding summer camps for autistic kids.

While the government is working towards providing IBI in schools, it "won't happen overnight,'' she said.

During last fall's election campaign, both the Progressive Conservatives and NDP vowed to clear the province's wait list. McGuinty wouldn't make a similar commitment, but the Liberals pledged $10 million for schools to deliver IBI therapy if re-elected.

"It's another broken promise by the Liberal government,'' Opposition Leader Bob Runciman said Tuesday.

"It's a significant problem for many, many families, and they're ignoring it at the moment.''

The lives of autistic children can drastically improve if IBI therapy is started early enough, said Taline Sagharian, whose 11-year-old son is autistic.

"The whole point is it's supposed to be started at an early age,'' she said.

"I don't know how that's going to be possible if the children are going to be sitting on a wait list for years and years.''

The New Democrats say most of the money is being spent to train principals and administrators on how to plan to provide the specialized therapy, rather than providing additional services for children.

"Without that IBI treatment or ABA treatment, their children fall further behind,'' said NDP Leader Howard Hampton. "So these parents just feel absolute desperation.''

Five families, including Sagharian's, are still waiting to see if they will be able sue the Ontario government and seven school boards for damages over funding for specialized treatment for autistic kids.

The group argues the province discriminates against autistic children because they can't always get both their therapy and education within the public school setting.

The Ontario Court of Appeal, which heard the case in February, is expected to release its decision this summer.

An estimated 50,000 children and 150,000 adults in Canada have autism.