The mayors of Canada’s largest cities are making a billion-dollar push for federal housing money just as the Liberals are set to finalize a national strategy, and the minister responsible is trying to manage expectations.

The mayors want the federal Liberals to set aside $12.6 billion during the next decade to help build new affordable housing units and alleviate a growing need in places like Toronto and Vancouver.

The lion’s share, about $7.7 billion, would go to repairing and maintaining existing units nationwide. A further $4.2 billion would go to building up to 10,000 new affordable housing units annually across the country. There is also approximately $700 million for a portable rental subsidy that wouldn’t be tied to a unit, but to a recipient.

It’s a major ask of the federal government as it works to finalize the second phase of its infrastructure program and allocate $17.7 billion for affordable housing, seniors homes, recreational facilities and child care — with each of those sectors competing for the cash.

“The highest need for most of us would be housing, and it’s not to say there aren’t pressing needs for seniors’ infrastructure, for culture and recreation infrastructure, and for child care space infrastructure, but without adequate, safe and decent dignified housing for families, those other services are less relevant,” said Edmonton Mayor Don Iveson, chairman of the Federation of Canadian Municipalities big city mayors’ caucus.

“We have needs in all of those other areas that social infrastructure could fund, but we don’t have a crisis in those other areas in the same way that we do around housing, especially in the largest cities.”

The federal government is set to unveil its national housing strategy in late November, laying 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.

The federal minister in charge of crafting a national housing strategy said Friday that the government plans to invest heavily to ease the housing crunch, but warned it may not be as much as everyone hopes.

Social Development Minister Jean-Yves Duclos 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.

“I think we can make a real and tangible difference in the lives of Canadian families,” Duclos said in an interview from Toronto.

“That requires resources, yes, and I think we’ve signalled in last year’s budget that we’re willing and able to provide some of these resources. That also requires a strong degree of collaboration across governments and across the private and social sectors.

“I’m very optimistic. Of course, I’m also very conscious of the challenges. It’s a long-term agenda. Short-term actions and attitudes matter very much. At the same time we know it will make a difference only progressively over time.”

The Liberals first budget set aside $2.3 billion for affordable housing, including money to build affordable rental units across the country.

Funding that flowed to Edmonton has helped replace 80 of 171 affordable housing units lost over the years because of inadequate spending, Iveson said.

Duclos unveiled details Friday of a $208.3 million fund to help build 4,000 units nationwide over five years. Developers and groups can apply for cash through the program that will test unique business models that may be too risky for some organizations to take on.

The Friday announcement is the first of two budget measures aimed at boosting the stock of rental units.

Duclos said details should be out by the end of the year about a promised five-year program that would make low-cost capital available to developers during the earliest, and riskiest, stages of development. The Liberals promised in their first budget to spend up to $500 million a year on the financing initiative to help build 10,000 units over the next five years.