OTTAWA - Less reliable data resulting from the Conservatives' census changes will force university researchers to rely more on grants funded by the federal government, professors say.

Researchers say they will no longer be able to reliably use data from the long-form census once it becomes voluntary in 2011. As a result, they will need more money from the federal government to buy substitute data from private organizations.

That will almost certainly mean that some research will never get funded and won't be able to proceed.

"As a researcher when you want to access the data then you'll have to pay for it," said Ellen Goddard, a rural economy professor at the University of Alberta.

Goddard uses data from the census to trace demands for food and food regulations across the country.

"We will be forced to try and find bigger research grants somehow and it's not clear how that's going to happen."

Much of professors' funding comes from organizations like the Social Sciences and Humanities Research Council and the Canadian Institute of Health Research -- agencies funded by the federal government.

"A lot of our researchers are now going to have to use their federal grant money to purchase private data, so in a sense it is not really saving the federal government a lot of money that way, it's adding more costs to universities and colleges," said David Robinson, the associate executive director of the Canadian Association of University Teachers.

Post-secondary institutions in Canada are already facing a funding crunch. This year's budget increased its spending on federal grant agencies by $32 million per year but only after it cut funding by $147.9 million over three years in 2009.

"The research budgets at universities are strained already," said Neil Besner, vice president of research at the University of Winnipeg. "We cannot fund internally all of the requests from our researchers to begin with and any additional strain on the budget would be a problem."

The changes are expected to affect other researchers in the social sciences as well. Professors who work in sociology, health, and geography will also need to find a new way to get this information once the last census in 2006 becomes unusable.

Industry Canada didn't provide a direct answer when officials from the department were asked if they would be increasing funding to federal grant agencies to help professors deal with the money crunch.

"The government finances researchers and data purchases through granting councils based on the merit of specific research proposals. This remains our policy," wrote Lynn Meahan, press secretary to Industry Minister Tony Clement, in an email.

She adds the new census will result in "useable and useful data that can meet the needs of many users."

The Conservative government announced in June that they would scrap the mandatory long-form census in favour of a voluntary version.

Economists, medical researchers, lawyers, social scientists and others opposed the decision on the grounds it would deny them important data they require to do their work. Former chief statistician Munir Sheikh resigned as head of Statistics Canada because he felt the voluntary version of the census would not produce reliable information.

Even if the government reinstates the original long-form census at a later date, it could continue to create problems for researchers. There will now be a gap in reliable data on Canadians between 2006 and 2011. The census is taken every five years.

The University of Alberta's Goddard says the data from the last census is soon going to be unusable.

"We're already on shaky ground without a nationally representative snapshot of the population to be able to characterize Canadians," she said.