Ottawa must bring back the long-form census, the organization representing Ontario's registered nurses, says.

As legislators prepare for next Wednesday's vote on Bill-C626, the Registered Nurses' Association of Ontario is throwing its support behind MP Ted Hsu's private member's bill, which would reinstate the long-form census.

The federal government decided to scrap the census in 2010 in favour of the shorter, voluntary National Household Survey.

Provincial and municipal governments, along with academics, business groups and policy makers who depend on the census data, decried the cancellation of the mandatory survey, fearing it would erode the quality of the information.

At the time, the RNAO warned it would hinder the government's ability to create responsive social, health-care and nursing policy.

"It's time for Prime Minister Stephen Harper and his government to fix its mistake, and restore the integrity of our national census," RNAO CEO Doris Grinspun said Saturday. "How can they govern effectively without the most accurate data? It seems this government would rather tell people what they need than respond to their actual needs."

In the absence of the long-form census, Statistics Canada knows less about average Canadian households than it did in the past, Auditor General Michael Ferguson said in a report last spring.