The B.C. Civil Liberties Association and the John Howard Society of Canada have filed a lawsuit against the federal government's use of solitary confinement in prisons.

The lawsuit, announced this morning in Vancouver, alleges isolating prisoners for up to 23 hours a day amounts to cruel and unusual punishment.

"Under the administrative segregation regime, prisoners can spend months and years in solitary confinement without even the benefit of an independent decision-maker to determine whether the confinement is justified," said Joe Arvay, lawyer for the two organizations.

In Canada, one out of every four prisoners in federal institutions has spent some time in solitary confinement.

Canada remains steadfast in its reliance on a broken and dangerous system. - Carmen Chung, B.C. Civil Liberties Association lawyer

"At a time when the rest of the world is scaling back the use of solitary confinement, Canada remains steadfast in its reliance on a broken and dangerous system," said Carmen Chung, senior lawyer at the BCCLA.

New York City officials agreed, on Jan. 13, to a plan to further reduce the use of solitary confinement by eliminating it for all inmates 21 and younger. When the change takes effect in January 2016, it'll put one of the largest prisons in the United States, Rikers Island, at the forefront of American jail reforms.

Various studies have documented the negative effects of long-term solitary confinement.

"Solitary confinement is increasingly being used to warehouse prisoners with mental-health issues even though it worsens mental illness," said Catherine Latimer, executive director of the John Howard Society of Canada.

The two human rights groups said they are looking for reforms around the use of segregation in prisons, not its abolition.

LIVE BLOG | Follow the announcement with CBC reporter Belle Puri