The Census Bureau would have to make severe cuts in the type of data it collects from American households and businesses if its budget is slashed 25 percent, as proposed under a bill being considered by the House Appropriations Committee, according to experts on the census.

The agency, which is closing half its regional offices to save money, has warned that cuts that big would likely mean an end to next year’s Economic Survey, which is conducted every five years and is used to calculate the nation’s Gross Domestic Product, among other things. There also could be deep cuts in the American Community Survey, a monthly survey of households that provides detailed information on a wide variety of habits, from commuting patterns to household income levels.

While the Obama administration has proposed reducing the agency’s budget from $1.15 billion to $1.02 billion, House lawmakers are considering a bill that would give the Census Bureau $885 million in 2012 — almost $300 million less. That is much deeper than the 6 percent cut being proposed for the Commerce Department, which oversees the bureau.

The Census Bureau has been criticized by some conservatives who argue its questions are intrusive. But lawmakers have said the cuts reflect economic realities, not any antagonism toward the bureau.

“In the absence of a comprehensive plan to rein in entitlements and our crushing debt, we are forced to focus only on non-security discretionary spending to achieve savings,” said Rep. Frank R. Wolf (R-Va.), head of the subcommittee that oversees Commerce.

In communications with House lawmakers, census officials have warned the impact would be long term.

“Cuts of this magnitude would mean the Census Bureau would have to terminate major statistical programs, cease critical data collection and vital benchmark reports on the nation’s economy, population and housing, and lay off as many as 700 employees,” the agency said.

Some lawmakers and census experts said the cuts would be counterproductive.

“Given the huge debate we are having about the state of the economy and what we should be doing for the next 10 years to grow jobs, it makes no sense to be gutting the data collection that tells us where we have been and where we are going,” said Rep. Carolyn B. Maloney (D-N.Y.).

Kenneth Prewitt, who headed the Census bureau during the 2000 count, said the cuts would make policymaking more difficult.

“It means the people who have to make decisions are going to scurry around to find second-rate, substitute information instead of sophisticated, carefully collected statistics that the Census Bureau, and only the Census Bureau, can provide,” he said.