A new rental housing tool is highlighting key electoral districts where voters are spending half or more of their income on housing to help inform voters and politicians before election polls open next month.

The Canadian Rental Housing Index released numbers and an interactive map Tuesday that broke down how much of their overall income Canadians are spending on rent across all 338 federal ridings.

The findings showed that Ontario has some of the worst rental housing affordability issues in the country. The five federal ridings, in which residents contribute the highest percentage of their incomes to rent, are all located within the Greater Toronto Area, according to the findings.

More than 30 per cent of renters in Willowdale, Thornhill, Richmond Hill and Markham are spending more than 50 per cent of their income on rent, the index found after analyzing numbers in Statistics Canada's 2016 long-form census.

In those same areas, it found that more than 55 per cent of renters are spending 30 per cent or more on rent.

Any household which spends 30 per cent or more of its gross income on housing has affordability issues, according to the Canada Mortgage and Housing Corporation.

"The data clearly demonstrates that our political leaders have not been able to find or implement meaningful solutions to the affordable housing crisis,” Marlene Coffey, the executive director of the Ontario Non-Profit Housing Association, said in a news releaseissued on Tuesday. “Ontario now has the dubious honour of being harder hit than anywhere else in the country."

The Canadian Rental Housing Index said its new report puts a face to those who are most impacted by Canada's national housing crisis. (Canadian Rental Housing Index)

The Ontario Non-Profit Housing Association was part of a coalition of national housing providers who contributed to the report, including the Federation of Canadian Municipalities, the Canadian Housing and Renewal Association, and the Aboriginal Housing Management Association.

The analysis also found that single mothers, Indigenous renter households, new immigrants, Canadians under the age of 30, and seniors are all facing higher levels of overspending on rental housing than the Canadian average.

"For a long time, the conversation around rental housing affordability in Canada has focused on the population as a whole, but the numbers clearly show several key, vulnerable groups are bearing the brunt of this crisis," Jeff Morrison, executive director of the Canadian Housing and Renewal Association, said in a news release.

"We very much hope that those seeking office in this election and Canadian voters will use this opportunity to push for more immediate and substantial action on this critical issue."

The online interactive tool aims to show both government leaders and voters the depth of the crisis in some of the federal ridings across the country, the creators said.

The federal election is set to take place on Oct. 21.