The Opposition Liberals and New Democrats want a parliamentary committee reconvened this summer to probe the Harper government's decision to stop requiring that one-fifth of households fill out a lengthy census questionnaire.
They want to Industry Minister Tony Clement called on the carpet to explain himself, saying the move will erode the ability of social scientists and policy makers to build an accurate picture of Canada.
It's the latest volley in what's become a culture-war battle between the right-wing Conservatives and their liberal-minded critics.
Mr. Clement is refusing, however, to consider changing course, saying the Tories feel that compelling people to answer questions about their personal lives is an unwarranted intrusion of privacy.
"In the past, the government of Canada received complaints about the long-form census from citizens who felt it was an intrusion of their privacy," Mr. Clement said in a statement released Tuesday.
"The government does not think it is necessary for Canadians to provide Statistics Canada with the number of bedrooms in their home, or what time of the day they leave for work, or how long it takes them to get there. The government does not believe it is appropriate to force Canadians to divulge detailed personal information under threat of prosecution."
Canadians are liable for a fine of $500 or three months in jail if they refuse to truthfully answer census questionnaires.
The Conservative decision still means all Canadians must complete the basic census form with eight questions about gender, age, marital status and relationships of people in the household.
But the longer form, with more than 50 questions, will now become voluntary, eroding Canada's only complete national database on education, income, employment, ethnicity and language.
Academics, economists and municipalities across the spectrum have already decried the move, saying census data is a precious resource, and Canada will be the only major country in the world to have no mandatory long-form census.
Liberal industry critic Marc Garneau warned the Tory move will undermine the ability of social programs to aid Canadians.
"[It's]a thinly veiled attack on the most vulnerable Canadians, and the federal government's ability to deliver progressive programs that help them," Mr. Garneau said.
NDP industry critic Brian Masse also says he's skeptical about Mr. Clement's argument that the mandatory long form was a major privacy concern for Canadians.
And the Liberals are urging an amendment to the Statistics Act to ensure the comprehensive long-form census remains mandatory for one-fifth of households.
"The Conservatives want to undermine the government's ability to enforce legislation and deliver social programs aimed at our most vulnerable," Mr. Garneau said, naming pay equity, labour market development, and immigration settlement programs as measures that could be affected.
The Tories rebut the criticisms, saying while the long-form census questionnaire will now be voluntary, it will be sent to many more Canadians.
But the Liberals estimate the Conservatives will have to spend an additional $30-million to send out more voluntary long form questionnaires.
(Photo: The Industry Minister takes the stage Tuesday night at Ottawa's Bluesfest music festival. The Canadian Press)