ST. PAUL — A federal judge refused Thursday to throw out the lawsuit challenging Minnesota’s treatment system for sex offenders, calling it “draconian” and “clearly broken,” and once again urged Minnesota lawmakers to make major changes.

Residents of the Minnesota Sex Offender Program contended in the lawsuit that the program amounts to prison-like confinement for people who’ve finished prison terms.

U.S. District Judge Donovan Frank wrote in a 75-page ruling that despite the state’s attempt to get it thrown out, the suit “easily survives dismissal.” While plaintiffs have yet to prove their case that the confinement is unconstitutional, Frank wrote, he made it clear in a strongly worded ruling that they have a good chance.

“Given the prison-like conditions described by Plaintiffs, and the lack of treatment and essentially no-exit regime alleged in this case, it may well be that, with a fully developed record, the Court will find the totality of the (Minnesota Sex Offender Program) system to be unacceptably and unconstitutionally punitive,” Frank wrote.

The program has come under fire in recent years over questions about its constitutionality and high costs. Nearly 700 sex offenders have been civilly committed to high-security facilities in Moose Lake or St. Peter after their prison terms were completed.

Minnesota has the highest number of civilly committed sex offenders per capita among 20 states with such programs, and more committed sex offenders than any state besides California and Florida.