California officials Friday asked the U.S. Supreme Court to block a lower court order that forces the state to quickly devise a plan to shed more than 40,000 inmates from its overcrowded prisons.

In a 46-page petition to Supreme Court Justice Anthony Kennedy, who handles emergency appeals from the Western states, California Attorney General Jerry Brown asked for an immediate stay of a three-judge panel's Aug. 4 order requiring the state to submit its prisoner release plan within 45 days.

Judges on the federal court panel Thursday rejected the state's bid for a stay, saying they've been "more than patient with the state and its officials" in the years-long legal battle over conditions inside California's prison system.

But California officials say the court has put the state in an impossible spot by requiring it to come up with a plan to reduce the prison population by nearly a quarter by Sept. 18.

"Every day that the three-judge court's order hangs over California, it places enormous strains on the state's existing resources and creates intolerable anxiety for both officials and residents of the nation's most populous state," state lawyers wrote to Kennedy.

State officials are asking Kennedy to put the order on hold while they appeal the entire ruling to the Supreme Court in the coming month.

The three-judge panel concluded that California's prisons have become so overcrowded that officials can longer provide inmates with adequate medical and mental health care, violating the U.S. Constitution's ban on cruel and unusual punishment.

The court ordered the state to reduce the prison population to 137.5 percent of capacity within two years, which would slash more than 40,000 inmates from a total number that exceeds 150,000.

Prison officials maintain that the judges overstepped their bounds, and that the ruling poses unprecedented issues for the Supreme Court in terms of state control over its prisons.

In the meantime, the Legislature has been unable in recent weeks to agree on a plan to reduce prison overcrowding and close a $1.2 billion gap in the budget for the state corrections system. Gov. Arnold Schwarzenegger backed a plan that would cut about 37,000 inmates from the prisons in the next few years, but it ran into resistance in the Assembly.