A proposed autism insurance mandate that divided advocates was struck down this week by New York’s governor who cited budget concerns.

The measure, which received unanimous support from the state’s legislature, would have required health insurance coverage of “evidence-based, peer-reviewed and clinically proven” autism treatments, a stipulation that proved contentious among autism advocates in the state.

Autism Speaks heavily lobbied for the bill, running advertisements and urging supporters to call daily to encourage Gov. David Paterson to sign the measure. But some parents of children with autism were vocally opposed to the legislation, arguing that its requirements were too stringent and could in fact prevent certain therapies from being covered.

In vetoing the bill Wednesday, however, Paterson didn’t weigh into the fray. Instead, the governor cited fiscal concerns. He estimated that the measure would cost the state at least $70 million a year — money which was not allotted in the state budget — and would also likely increase health insurance costs for residents.

“I am extremely sympathetic to the very real struggles faced by the families of individuals with ASD,” Paterson said in his veto. “It will be a subject of my continued advocacy as a private citizen. But now I am governor and I cannot sign a bill that would impose costs that the legislature does not fund.”

Officials with Autism Speaks are refuting Paterson’s figures, arguing that the bill would cost no more than $30 million once fully implemented and would increase private insurance premiums by less than 0.65 percent. They are now working with legislators and may push for a vote to override the veto.

Currently, 23 states mandate that health insurers cover autism, according to Autism Speaks. New York is the second state — following South Carolina — where autism insurance legislation was vetoed.