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 should n'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 .
Gov . Jerry Brown will seek a stay of what he calls `` unprecedented '' court order . A federal court orders prison population to fall to 137.5 % of capacity . Original lawsuits were filed when overcrowding was at 202 % of capacity . Federal court ruling threatens California with contempt but defers action .