TORONTO -- Parents of children with autism gathered outside the Ontario legislature Thursday calling on the government to reverse a decision to defund intensive therapy for children five and older, saying they feel their kids have been abandoned.

Children and Youth Services Minister Tracy MacCharles said she is listening to parents, and there is "room for conversation about how this program will play out over time."

"I'm not ruling things out," she said. "I'm listening to all the experts...I'm taking that all in, and the ministry is too, to make sure we're putting the right focus on this program as it rolls out."

The Liberal government recently announced a new Ontario Autism Program with $333 million in funding, which will ultimately integrate Intensive Behavioural Intervention and Applied Behavioural Analysis therapies, currently in two separate streams, into a flexible service they're calling enhanced ABA.

But the changes include limiting IBI to children between two and four. The government says expert advice is to focus on children in that developmental window. Parents dispute that IBI is less effective once children are five.

The government says 16,000 more children will receive services -- mostly ABA -- and that IBI wait times will go down, but parents say that comes at the expense of children who are or will soon be five years old.

Children over four who are already receiving IBI or will very soon will start to be transitioned to the new program at their six-month assessment. Rebecca Haight's son is in that category.

"I am very lucky and I will beg, borrow and steal to figure out how to keep my kid in more therapy because that's what he needs," she said. "He does not need enhanced ABA. It's not IBI."

Haight's son knows the alphabet in four languages but can't communicate well.

"He's just kind of locked inside of himself," she said. "He can't say my tooth hurts. He just had to have dental surgery and we didn't know he was in pain. He can't express his needs or if he's hurt."

Kristen Ellison also considers herself relatively lucky. Her five-year-old son started IBI about the same time as the changes were announced and he has had "unprecedented results," she said.

"He mastered two goals in five days, which is more development than we've seen in a year," Ellison said.

Under the new rules, parents whose children are removed from the wait list because they are older than four will get $8,000 to pay for therapy as they wait for the new program. But parents say that won't last long.

Steven Sherwood hopes his four-year-old son will receive service before he turns five in March, but in the meantime he and his wife have been paying for private therapy. They can only afford 10 hours per week.

"You can just see it's starting to work," he said. "We can only wait with incredible enthusiasm and hope for IBI to begin for him because we just know it's going to unlock so much in him."

Progressive Conservative Leader Patrick Brown told the protesting parents that the government should "correct course" and promised that if his party wins the 2018 election, it will fund IBI after age five.

NDP critic Monique Taylor was kicked out of the legislature Thursday after a lengthy rant on the autism changes.

"This is wrong," she shouted. "Do the right thing."