OTTAWA — Canada's packed, crumbling jails -- rife with illness, addiction and violence -- are endangering the ability of offenders to one day rejoin society, the federal prison ombudsman says.

In releasing his annual report, Correctional Investigator Howard Sapers warned that prison crowding leads to increased tension, frustration and violence.

He said the difficulties would only grow for the most vulnerable inmates as numbers swell due to Conservative legislation and policies.

"Of particular concern to me this year is the climate inside Canada's federal penitentiaries. This climate is increasingly harsh, tense and stressed. And it's undermining the rehabilitation efforts," Sapers told a news conference.

"Many of our prisons are overcrowded. The physical infrastructures are deteriorating. Offender populations today include a disturbingly large number of those with mental illness."

In addition, the federal Correctional Service is grappling with a more complex type of offender, he said. "These profiles include histories of gang membership, chronic illness and substance abuse."

The use of force by prison authorities -- who dispatch emergency response teams, release pepper spray and draw their guns to quell problems -- is on the rise, Sapers added.

Most offenders eventually return to society, so it's in everyone's interest to ensure they are treated fairly behind bars, he said.

The prison population is expected to climb due to a flurry of federal legislation that will result in longer sentences.

The ombudsman's report says that when the new measures take full effect "there will almost certainly be disproportionate impacts on Canada's more distressed and vulnerable populations."

The use of double-bunking -- the placement of two offenders in a cell designed for one -- has increased by more than 50 per cent in the last five years, Sapers said.

"Given the high rates of mental illness, drug addiction, violence, communicable disease and gang affiliation, double-bunking is not sustainable, nor is it good or safe correctional practice."

The government says it anticipates adding over 2,700 beds to men's and women's prisons across Canada in coming years. There are currently about 13,000 people in federal custody.

The aboriginal incarceration rate is more than double the national average, Sapers noted. "An astounding one-third of all female incarcerated offenders are of aboriginal descent."

The office of Public Safety Minister Vic Toews said the government was "taking action to repair the failed Liberal corrections system" by initiating much-needed reforms.

It pointed to the investment of more than $50 million to help the Correctional Service address mental health issues in recent years. "This government takes its responsibility for the safety of our communities very seriously, and we will continue to do more."

Sapers noted the prison service's commitment to mental health needs, but said additional progress is needed to prevent deaths like that of teenager Ashley Smith, who committed suicide in 2007 after being shunted between institutions.

"As a society, we are criminalizing, incarcerating and warehousing the mentally disordered in large and alarming numbers," the report says.

It cites shortcomings in the federal prison system to address mental illness, including:

• a lack of recruitment and retention of mental health professionals;
• inappropriate facilities to meet growing needs;
• no money to build necessary care units;
• insufficient plans to manage high-needs mentally disordered offenders;
• and over-reliance on segregation for prisoners with mental health concerns.

The Correctional Service says it wants to make offenders more accountable, eliminate drugs in prisons, improve correctional programs, modernize buildings and strengthen links to the community.

Sapers says his concern is not with these commendable goals, "but with the process and direction we are taking to get there, and the unintended consequences of simple solutions applied to complex problems."

NDP public safety critic Don Davies said the correctional investigator's findings amount to a "complete and thorough indictment of the Conservatives' approach to prison policy."