SACRAMENTO (AP) — The leader of the state Senate on Wednesday backed Gov. Jerry Brown's proposal to send thousands of inmates to private prisons rather than free them early to comply with federal court orders to reduce prison crowding.

But Senate President Pro Tem Darrell Steinberg insisted that the state should also spend more money on mental health and substance abuse treatment programs that would reduce the prison population in the long run.

Corrections Secretary Jeffrey Beard told The Associated Press this week that the Democratic governor will soon ask federal judges to let the state send at least 4,000 inmates to private prisons to help cut 10,000 inmates from the state's major prisons by year's end.

The proposal came after the U.S. Supreme Court rejected Brown's request that the justices delay a lower court order requiring that the state reduce the inmate population to about 110,000 inmates to improve prison conditions.

Steinberg, D-Sacramento, agreed with the Democratic governor that contracting for prison beds to meet that requirement would be better than freeing a similar number of inmates before they complete their full prison sentences.

The program would be expensive but money could come from unanticipated tax revenues that have been increasing as the economy recovers, Steinberg said.

However, renting prison cells "does not do a single thing to reduce the prison population on a long-term basis," Steinberg said. "Investing in substance abuse and mental health treatment keeps people out of prison once they leave."

Brown may not need to ask lawmakers to appropriate money for the prison contracts because the courts have waived state law and the state constitution in ordering the governor to take whatever steps are necessary to reduce the prison population by year's end.

Administration officials have not said how much the private prison plan would cost.

The plan requires federal judges to approve that option.