The Federal Court will hear a complaint Monday by a French-Canadian group that opposes the government's move to replace the mandatory long-form census with a voluntary survey.

The Federation of Francophone and Acadian Communities of Canada has asked the court in Ottawa to void the new policy from Stephen Harper's government, but it also wants an injunction that would keep the new voluntary national household survey from being distributed this year.

Marie-France Kenny is the president of the Federation of Francophone and Acadian Communities of Canada, which opposes the federal government's move to scrap the mandatory long-form census. (CBC)

The federation, which has also filed a complaint with Canada's official languages commissioner about the census change, argues that the government's new policy violates not only the Official Languages Act, but also the Charter of Rights and Freedoms.

In late June, Industry Minister Tony Clement announced the long-form part of the 2011 census would no longer be mandatory because of privacy concerns.

Ever since the move was announced, statisticians, researchers, academics, municipalities, religious groups and others have decried the move, arguing it will result in skewed and unreliable data.

"Our fear is that government will no longer have the information it needs to design and elaborate programs and services," said Marie-France Kenny, the federation's president.

"This data is needed across the country," she said. "We're Canadian citizens. We're not just French citizens, so of course we understand the need for this information for the entire country."

Liberal MP Carolyn Bennett, who attended a town hall meeting in her Ontario riding of St. Paul's on Sunday, said her party will table a motion in the Commons on Tuesday to reinstate the mandatory long census. She has already submitted a private member's bill that she hopes will be tabled within weeks.

"From violence, poverty, the environment, shelter education — this is how we keep people well, how we plan for the country and, in some ways, is our constitutional responsibility to francophones, to aboriginal peoples," she said.

In August, the government announced two questions on languages would be added to the mandatory short-form census to fulfil its legal obligations under the Official Languages Act.

All Canadians will still receive a mandatory short-form census and one in three households will be sent the new voluntary national household survey as well. Previously, one in five households were sent the mandatory long-form census.