Faith groups are the latest contingent to complain about the federal government's decision to cut out the long-form census.
Both the Canadian Jewish Congress and the Evangelical Fellowship of Canada have written to the Conservative government to voice their concerns.
They say they rely heavily on the data from the census to better serve their communities.
Questions on religion are included in the long census every 10 years, with the next such version coming up in 2011.
However, Industry Minister Tony Clement said he has received dozens of letters supporting the move to replace the long-form census with a voluntary household survey.
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The Canadian Medical Association Journal also criticized the Tories for what it calls a decision based on "ideology."
The traditional census is an "essential tool" in the planning and delivery of health services, the journal said.