MONTREAL -- Montreal's homeless shelters are facing a critical bed shortage.

Staff and management at the shelters say they need about 600 more beds and they want them to be available 24/7.

The pressure is mounting with winter just a few months away, and Montreal's homeless population is growing.

"We need more capacity as we come closer to winter," said Old Brewery Mission president James Hughes. "But, we don't just need extra beds, we also need a change in thinking about what we're doing with that extra capacity."

In June, seven Montreal-area shelters released a five-year plan to reduce homelessness in the city that called for the additional beds that would always be available.

"In the past, it's only been 12 or 16 hours that's been covered in terms of funding," said Hughes. "We've got to put that model to bed and not ever recreate it. Let's go forward with a model that's much better."

Welcome Hall Mission executive director Sam Watts said the 24-hour model allows shelters to provide the kinds of services that help people leave homelessness.

"During the day is the best time really to meet with intervention workers, to meet with social workers, to meet with housing experts," said Watts. "You can't do that at night."

Watts said it's a proven model, and, in the summer, the Old Brewery Mission and Welcome Hall opened at 24-hour shelter with 150 beds at the Hotel Dieu Hospital.

"We've managed to help 76 people get back into housing since the onset of that particular project, and that's in the context of a Montreal with a bit of a housing shortage," said Watts.

Hughes said Montreal's lack of affordable housing is a major factor contributing to a rise in homelessness.

"There is just less and less and less housing available for extremely poor people," said Hughes. "There's basically a zero vacancy rate for the kind of housing that our clientele needs."

Hughes added that when governments invest in lifting people out of homelessness, they save on emergency services bills.

"It's a great financial investment, but more importantly, it's a great moral investment," he said. "Having homelessness of any kind in our city is really tough to see and I think we all agree that it's something that we need to have a lot less of."

The Quebec Health Ministry said it will announce a plan to address homelessness in the coming weeks which will include a significant increase in the number of beds.