Demand for Montreal's food bank services is up a third compared to last year in what is becoming "an alarming situation," according to the city's largest food security agency.

More than 18,000 Montrealers turned to food banks in 2009, a 32 per cent increase in demand for emergency aid, compared to 2008, said Harvest Montreal, in its Bilan Faim report issued on Thursday.

Seniors, children and single-income households are overrepresented in the increased demand, fuelled largely by this year's recession, said the non-profit organization.

The working poor may feel stretched too far after losing their jobs in the economic downturn, said Zakary Rhissa, a Harvest Montreal worker. And with grocery stores also feeling the recession pinch, "we have increased demand, but 21 per cent less donations," Rhissa said.

NDP MP Thomas Mulcair says Canada's current employment insurance program is partly to blame.

"The very fact that people who are on employment insurance can't get by without a food bank is an indication that we're not being fair, the system does not work, and the federal government has a large role to play in that," he said.

Food banks have long tried to get the attention of policy-makers, and the situation is going to get worse, said Harvest Montreal director Johanne Théroux.

"Given the current tendencies, and after analyzing results from the report, the question of urban food security and hunger could become our city's greatest challenge this century," she said Thursday, in an interview with CBC's French-language service.

The food bank is asking for increased government funding, and more innovation in corporate funding, including a proposal to create a program encouraging food producers to donate time and goods to the cause.