The Federal Government is backing away from comments that low-income earners should be able to opt-out of compulsory super.

According to The Australian, a spokesman for Treasurer Scott Morrison said the government is not considering a move to allow mothers, part-time workers and casual workers earning less than $37,000 a year to opt-out of paying into superannuation accounts.

The statement comes following comments from Deputy Prime Minister Barnaby Joyce, who said workers on low incomes would be better off in the long-term if they used the money allocated to super to invest in an asset such as a house.

The Federal Opposition and unions jumped on Joyce's comments, with Opposition spokesman for superannuation Jim Chalmers accusing the government of trying to "wreck super", The Australian said.