TRENTON - Gov. Christie on Monday vetoed legislation aimed at restricting the use of solitary confinement in New Jersey's prisons, declaring that the state does not use the controversial disciplinary practice.

"The irresponsibility of this bill, and the resulting peril in which it could place both inmates and corrections officers every day, is truly breathtaking," Christie, a Republican, wrote in his veto message.

"This is the danger of legions of Democratic legislators blindly following the rhetoric of prime sponsors who typically legislate by bumper sticker slogans," he said.

The legislation would have barred "isolated confinement" for members of a "vulnerable population," including inmates 21 or younger, 65 or older, the mentally ill, and sexual minorities.

No inmate could be held in "isolated confinement" - confined to a cell alone or with others for at least 20 hours a day, "with severely restricted activity, movement, and social interaction" - for more than 15 consecutive days or 20 days in a two-month period.

Christie and the state Department of Corrections said New Jersey placed inmates in "restrictive housing," not isolated units. The ACLU called that a distinction without a difference.

"Christie's veto of solitary confinement reform means that on any given day hundreds of New Jersey inmates, if not thousands, will be punished through a practice widely considered torture, and for no one's benefit," Alexander Shalom, a senior staff attorney with the ACLU's New Jersey chapter, said in a statement.

"The Department of Corrections covers its eyes to the reality of solitary confinement, and Christie helps pass out the blindfolds," he said.

Inmates are segregated into housing "when medically necessary" or for safety reasons, sometimes voluntarily, Christie said.

About 1,200 inmates were in "restrictive housing" as of April, according to the Department of Corrections.

Some 20,300 people are incarcerated in state correctional facilities, according to department data.

State Sen. Raymond J. Lesniak (D., Union), a bill sponsor, said Christie's veto "completely contradicts his supposed commitment to long-needed reforms to a prison system that is cruel and counterproductive."