OTTAWA -- Canada's cities say housing is becoming increasingly unaffordable at every income level, and the federal government's plans for a national housing strategy need to include billions more for social housing to confront the problem.

The Federation of Canadian Municipalities says wait lists for social housing are growing, and one out of five renters spends more than half their pre-tax salary on shelter.

"We know that safe and affordable housing is the bedrock of communities where people want to live, raise their families and start businesses, said federation president Clark Somerville.

"Instead, we're facing a housing crisis, and we need to fix this now."

Especially vulnerable are newcomers to Canada, Aboriginal Peoples, single moms and seniors living alone.

The federation says Ottawa has already opened the door to more federal involvement in fixing the housing crisis by putting forward some funding in the last budget.

But now, the federation says the housing strategy needs to carve out $12.7 billion over eight years to protect existing social housing, prevent homelessness, build new units and provide a portable housing allowance to needy renters who can't find affordable housing.

The request from cities across the country reinforces similar demands from the big-city mayors made earlier this month.

"We finally have a window of opportunity to tackle the housing crisis," Somerville said. "The federal government has a big mandate to invest in social infrastructure. Now we need that big decision to make affordable housing a priority."

The Liberal government opened a national consultation on a housing strategy in June. The deadline for submissions is today and the results are to be released Nov. 22, which is National Housing Day.

Ottawa has been an on-again, off-again player in the field of social housing over the years, dramatically scaling back its funding in the early 1990s and putting some support back on a patchwork basis a decade later.

As a result, the foundation says the housing stock has deteriorated and long-standing operating agreements have been expiring without a plan to maintain the federally supported units.

At the same time, housing prices have soared in some big cities, putting pressure on rental markets.

"As home ownership becomes prohibitively expensive in many cities, modest income earners are driven to choose between shouldering heavy debt and turning to rental markets -- further raising demand and prices," the submission says.

The federal government's approach to homelessness also needs some work, the organization said -- echoing comments put forward on Thursday by two research groups focused on the state of homelessness in Canada.

They, too, want to see Ottawa ramp up spending on affordable housing to make up for the lack of action over the past couple of decades.

If the federal government doubled its allocation to affordable housing over the next 10 years, it would effectively eliminate most homelessness, say the Canadian Observatory on Homelessness and the Canadian Alliance to End Homelessness.

The national housing strategy is expected to lay out how the government plans to help with affordable housing, homeless shelters, rental units and the high cost of home ownership in some Canadian cities. Federal officials see the plan as central to the government's longer-term goals to reduce poverty rates nationwide.

Social Development Minister Jean-Yves Duclos, who is in charge of crafting the strategy, has said that the government plans to invest heavily to ease the housing crunch, but has also warned it may not be as much as everyone hopes.

Duclos has said the government is looking to make the most efficient use of available funds, because no government can ever spend what stakeholders would like to see spent on affordable housing.