Prime Minister Stephen Harper says it is not "appropriate" for the government to threaten Canadians with jail time or fines for failing to fill out the mandatory long-form census when asked to do so.

Prime Minister Stephen Harper responds to reporters' questions at the Vancouver Aquarium on Monday. (CBC)The comments marked the first time the prime minister has weighed in publicly on the Conservative government's decision to scrap the mandatory long census form and replace it with a voluntary survey.

Speaking to reporters Monday after a funding announcement at the Vancouver Aquarium, Harper said he understands some Canadians are reluctant to give "detailed personal information" sought after by the government.

"I know some people think the appropriate way to deal with that is through prosecuting those individuals with fines and jail terms," he said. "This government will not do that."

Instead, the prime minister said the government will work with the public to get co-operation on providing the information.

Statisticians, religious groups, as well as some provinces and municipalities have joined a growing chorus of groups decrying the government's move to cancel the mandatory long survey, saying it will lower the quality of data gathered by the census and hinder policy-makers' decisions.

Opposition parties have accused the Conservatives of manufacturing a crisis, citing the fact that no one has ever been sent to jail for refusing to fill out the mandatory form.

Last month, Munir Sheikh, the former head of Statistics Canada, told the industry committee he resigned because he took issue with media reports quoting Industry Minister Tony Clement suggesting the agency was supporting the government's move to end the mandatory survey.

Sheikh told MPs that "no statistician in the world" would agree that a voluntary survey could serve as a substitute for a mandatory census.