A MOTHER of two autistic boys says she will be forced to sell the family home because the state government broke its promise to build an autism-specific P-12 school at Laverton.

Derrimut's Maria Ager said her family had to sell so they could move closer to another school because her nine-year-old son had to leave Western Autistic School in December.

The school caters only for children in prep to grade 3.

"My younger son can't go to mainstream school, there's no way," Ms Ager said.

"He can't cope with 800 kids at a school or 25 kids in one class. His IQ is about 49. His speech has improved, but it's not like the communication that we have. He still doesn't know how to read and write."

She said both boys needed a daily routine.

"Everything needs to be structured. If I do change anything, all hell breaks loose."

While her eldest was "high-functioning" and attended a mainstream school, he wasn't always able cope. Though his borderline IQ of 76 made him ineligible for a special-needs school.

Williamstown MP Wade Noonan has repeatedly called for a review of assessment criteria for children with autism. The Education Department has repeatedly refused.

"He's going to be 12 soon," Ms Ager said of her eldest son.

"He's going to be dealing with 15, 16, 17-year-olds. If he goes up to a kid and says something the wrong way, he could get his head bashed in."

Ms Ager was among parents who protested for an P-12 autism school before November's state election.

Western Metropolitan Liberal MP Bernie Finn rallied alongside other parents of children with autism.

Ms Ager said: "They [Liberals] said, if you vote for us you're going to get the P-12 school, and since they got in we haven't heard anything about it.

"They've failed us."

Action for Autism Education spokeswoman Angela Hickey-Sorbello said western suburbs parents wanted equal rights as the rest of Melbourne. "We want equity with other regions; $16million went to the eastern region for a P-12 school. We're sick of waiting. The west has been waiting too long."