The White House has proposed $878 million for the bureau in its 2007 budget, but the House voted last month to give the agency $815.7 million, and a Senate committee voted this week to provide $828 million, The Washington Post reported.
Bureau officials declined to comment on the cuts, the newspaper said, but advocates for the agency said the lower funding would threaten the accuracy and cost-effectiveness of the 2010 head count.
One effect would be that the bureau would have to drop plans to use hand-held computers to collect census data. Also, the bureau would be unable to document fully the number of people living in group situations such as prisons, college dormitories and mental hospitals.
"It would be devastating," said Rep. Frank Wolf, R-Va., chairman of the Appropriations subcommittee, which funds the census.
He told the Post he would convene a hearing late this month "to make the case publicly how important this is."