In its haste to finish work on the 2000 budget last month, Congress made a $4 billion "drafting error" that has come back to haunt it.

The mistake was made in an obscure "miscellaneous appropriations act," passed along with the last of the major spending bills, that offset some of the spending by delaying for two days the last pay date for military personnel and shifting some funds from the Federal Reserve to the Treasury.

About $4 billion of those savings should have been credited against day-to-day government spending, but by mistake the savings were credited against entitlement, or "mandatory," spending. Republican leaders discovered the error before adjourning last month but decided not to do anything about it.

This week the Congressional Budget Office (CBO) cited the mistake in a report that recommended an across-the-board spending cut to correct the problem.

By law, the administration has final say over whether to order an across-the-board cut. Yesterday, a White House official said the administration would not follow the CBO's recommendation, and CBO officials agree that in the end the mistake will likely be ignored.

"Though this may have been a mistake, I don't think it makes a difference," a CBO official said yesterday. "It only matters to us budget geeks."