Los Angeles (CNN) -- California Gov. Jerry Brown will seek an immediate stay of what he called an "unprecedented" federal court order to release almost 10,000 inmates to relieve prison overcrowding by the end of the year, he said Thursday.
A three-judge federal court panel ordered the state to reduce its prison population to 137.5% of design capacity by December 31 and threatened to find the state in contempt if California does not report on its progress every two weeks, Thursday's ruling said.
California has the nation's largest prison system and says it has been reducing overcrowding.
The case grows out of lawsuits filed in 1990 and 2001 that alleged overcrowding is at the core of a domino effect of unsafe and unhealthy conditions for those on both sides of the iron bars. When plaintiffs filed motions to convene the three-judge court panel in November 2006, California's prisons were at 202% of design capacity.
In 2011, the U.S. Supreme Court upheld a three-judge federal panel's determination that California's medical and mental health care for inmates falls below a constitutional level of care and that the only way to meet the requirements is by reducing prison crowding.
The Supreme Court in 2011 found that California's shortcomings in prison medical and mental health care resulted in "needless suffering and death" and recognized the federal court's prison reduction order was "of unprecedented sweep and extent," Thursday's ruling said. The high court affirmed that order in full in 2011.
On Thursday, the three U.S. District Court judges expressed impatience with California officials, the defendants in the case.
"The history of this litigation is of defendants' repeated failure to take the necessary steps to remedy the constitutional violations in its prison system," the order said. "It is defendants' unwillingness to comply with this Court's orders that requires us to order additional relief today."
The three-judge panel added that the plaintiffs' request for a court order to show why California shouldn't be held in contempt "has considerable merit."
"Our first priority, however, is to eliminate the deprivation of constitutional liberties in the California prison system," the three judges said in their ruling. "We will therefore DEFER ruling on plaintiffs' motion, and defer instituting any contempt proceedings related to defendants' prior acts until after we are able to determine whether defendants will comply with this order."
Court documents also show that "DEFER" was not only all capitalized but also printed in bold face.