OTTAWA - The Liberals have introduced a private-member's bill in the House of Commons to bring back the mandatory long-form census.

They say the Conservative government would not be able to ignore the bill, as it did with a motion on the census passed in the Commons on Wednesday.

The bill would entrench the long-form census into the Statistics Act, while removing the threat of jail time for people who refuse to fill it out.

The NDP and Bloc Quebecois have already said they would support the bill.

But there is little chance a private member's bill would be able to get through the Commons and Senate by the time the 2011 census process starts in March.

The Conservatives eliminated the mandatory long-form census and replaced it with a voluntary survey because they said they can't support coercing Canadians for private data.

The short-form census, the census of agriculture and the labour force survey remain mandatory.