With the state's budget deadline rapidly approaching, Gov. Rendell Saturday warned that proposed Republican budget cuts would reverse years of progress in autism treatment, and he urged parents of autistic children to pressure lawmakers to vote for an income tax hike to preserve the programs.

Rendell, a Democrat, said his proposal for a temporary, three-year state income tax increase had encountered stiff opposition, and that some lawmakers had been intimidated by the anti-tax sentiment.

"We have the power to change things," Rendell said of his administration and the legislature. "Take a little risk. Do the right thing."

Republicans responded shortly after Rendell's comments, noting that cuts to autism services had been limited to public awareness and other information programs and would not affect treatment.

Senate Appropriations chairman Jake Corman of Centre County said there was "zero" chance that an income tax hike would pass the Republican controlled Senate.

"I understand that the governor is well intentioned," he said. "But this is not the time to ask the people of Pennsylvania for more money. People are hurting."

Rendell made his remarks at a rally Byrn Mawr College in support of expanded autism services. Stating that he needed six votes in the Senate, he urged the 100-plus persons in attendance to contact lawmakers and urge them to vote for the tax increase.

Otherwise, years of hard won advances would be reversed, he said.

"All cuts are not the same," Rendell said. "We rejected these cuts because the programs are so important."

Of his proposed tax increase, Rendell said: "'We can do this if we can convince the Senate Republicans to do those things that we think are the right thing to do."

Rendell's talk Saturday on potential cuts to autism services echoed his earlier warnings as he traveled the state last week, where the governor noted that economic development programs would be reduced if the legislature fails to raise taxes and the state's $3.5 billion budget gap is not closed.

Under the state constitution, the governor and legislature have until June 30 to adopt a new budget, but Corman and others say it is highly unlikely that they will make that deadline. For one thing, he predicted that Democrats themselves would have a hard time finding votes for a tax hike in their own caucus.

While it faces a deadline, it is likely that the state will be able to function for at least a few weeks while Rendell and the legislature try to find common ground.

The rally at Bryn Mawr's Graduate School of Social Work and Social Research was attended by autistic children, their parents and other family members.

One theme emerged: services for autistic children, though they have expanded in recent years, virtually disappear once they reach the age of 21. As more and more persons are diagnosed with the disorder, the need for state programs to back up hard pressed parents only will grow.

"For parents with autistic children, the single most important number is 21, when educational services end," said David Fine, a Harrisburgh lawyer who attended the rally, and whose son, Kenneth, is autistic. "We know our efforts will not be enough."

Rendell contended that his proposal for a temporary income tax hike was a modest inititiave. At 3.07 percent, the state currently has one of the lowest personal income tax rates in the nation, far below those in New York and New Jersey.

Rendell is proposing a 16.5 percent hike to 3.57 percent that would end after three years. Even with the increase, he said, Pennsylvania's income tax rate would be the third lowest in the nation.

He estimated that the tax hike would add about $5 a week to the tax bill of a family with an annual income of $50,000, the average in Pennsylvania.

Contact Staff Writer Chris Mondics at (215)854-5957 or cmondics@phillynews.com.