MINNEAPOLIS — A federal judge declared Minnesota’s sex offender treatment program unconstitutional Wednesday and gave the state’s political leaders one last chance to propose solutions that would protect the “fundamental rights” of more than 700 people locked up indefinitely before he imposes remedies himself.

U.S. District Judge Donovan Frank sided with patients who were civilly committed to the MinnesotaSex Offender Program after completing their prison sentences. He agreed that given the program’s 20-year history, no one in it has “any realistic hope of ever getting out,” even if they do well in treatment and are at low risk of committing new crimes. Instead, he said, it’s undisputed that some residents no longer meet the criteria for commitment or could be released into less-restrictive settings.

“The stark reality is that there is something very wrong with the state’s method of dealing withsex offenders in a program that has never fully discharged anyone,” Frank wrote.

Yet Frank ordered no immediate changes or releases, instead urging top political leaders to bring proposed remedies to proceedings that will begin in August. Otherwise he made it clear he would impose his own. He suggested more than a dozen, including more reliance on alternate less-restrictive facilities. He said he may appoint a special master to ensure compliance. And he warned that a failure to come up with an acceptable plan could lead him to order the closing of the St. Peter and Moose Lake facilities or the extensive release of patients.

Minnesota has struggled for years with the rising costs of its policy on sex offenders, spending millions to expand and update the two the prison-like facilities. It costs more than $124,000 a year to house just one resident, triple the cost of prison.

But lawmakers, many fearful of appearing soft on crime, have resisted any substantive changes. Just this year, legislators declined a proposal to buy land for and design two facilities aimed at housingsex offenders on course for eventual release. They also declined to provide requested funds that would have allowed the program to carry out some of the judge’s recommendations, such as periodic risk assessments for each resident.

“This is a very powerful statement by Judge Frank. I think it’s an indictment of the Minnesota political system,” Dan Gustafson, the lead attorney for the plaintiffs in the class action lawsuit, said at a news conference. “These issues are not new to the state of Minnesota but the political system has failed to act on it, and I think that frustration comes out in the judge’s opinion pretty clearly.”