Lawmakers and advocates for crime victims joined together Monday to file a lawsuit in San Diego challenging a new law that permits the state to set free up to 6,500 prison inmates this year before their original sentences are completed.

"Victims have a right to expect sentences will be carried out. ... It is very clear that what they are doing is releasing prisoners early to ease overcrowding. That is flat out unconstitutional," Assemblyman Ted Lieu, D-Torrance, said in an interview.

Assemblyman Nathan Fletcher, R-San Diego, said any programs that allow prisoners to walk out before serving their sentences has to be scrutinized in light of problems plaguing prisons and parolee oversight.

"We need to do everything we can to stop any release of inmates and do a full review of the corrections system to put reforms in place," Fletcher said.

The lawsuit filed in San Diego County Superior Court is the second bid to have the law overturned. A Placer County judge earlier this month tossed out litigation filed there.

Sponsored by Crime Victims United, the lawsuit alleges that the plan unconstitutionally conflicts with a 2008 voter-approved initiative that prohibits early releases to solve overcrowding problems, among other victims-rights provisions.

Gordon Hinkle, a spokesman for the California Department of Corrections and Rehabilitation, said the legislation has been incorrectly characterized as an early-release program.

In an e-mail message, Hinkle said the legislation allows inmates to earn credits of up to six weeks annually that would cut short their original sentence. For example, they would have to complete a vocational training course or earn a general education development diploma.

"These programs are proven to reduce crime and assist in a successful transition into society," he said.

Fletcher, though, said, "Getting out early is early release."

Said Hinkle: "No serious or violent felons, no sex offenders, and no gang members would be eligible for the new parole terms created by the law."

The lawsuit contends that Proposition 9, also known as Marsy's Law, prohibits any new programs such as the one approved in the legislation from cutting jail sentences.

Going to court was the only recourse, said Nina Salarno Ashford, a Crime Victims United board member.

"Our cries out to the governor and to CDCR have fallen on deaf ears and have been ignored," she said.

"And now because it has been ignored, the governor and the California Department of Corrections and Rehabilitation see fit to jeopardize every citizen in the state of California by implementing early release programs." Her group contends that as many as 40,000 felons could walk free under the policy, not the 6,500 estimated by the state.

"They will tell you, the governor and CDCR, that these are nonviolent people that they are releasing, but they will not tell you that nonviolent in California spans a wide section of crimes including domestic violence, child and elder abuse, 19 sexual assault crimes and a host of other crimes," she said.

Hinkle, however, argues: "Prisoners still have to complete their sentences and are subject to disciplinary actions and loss of credits in cases of bad behavior. The new law also has a reform component related to parole, which the department feels is an improvement to public safety since it allows us to focus our resources on those most serious and violent offenders that are most likely to re-offend," he said.

Crime Victims United also made it a point in its filing to note that the litigation targets only state prisons; it does not apply to local or county jails, such as in San Diego where cells were opened for 260 nonviolent offenders in late January.

The group filed the lawsuit in San Diego County because it has a state prison and the California attorney general has an office in the county.