Washington ? The government ran a $159 billion deficit in the fiscal year just ended, the Bush administration said Thursday, punctuating one of the federal budget’s worst nosedives ever just 12 days before elections for control of Congress.

The figure was not a surprise and largely reflected an ongoing dip in federal revenue collections. But it was nonetheless breathtaking for its contrast with the $127 billion surplus the second-largest ever shown by the government’s books just a year before.

Though Democrats hope the budget’s deterioration will help them in next month’s elections, many analysts and officials from both parties believe the return of deficits after four straight years of surpluses will have a minimal political impact. That is because the public seems more focused on the flagging economy and the threat of terrorism and blames them not politicians for the revived red ink.

In a written statement, White House budget director Mitchell Daniels blamed the red ink on needed defense and domestic security expenditures, and the end of a federal revenue surge fed by the booming economy of the late 1990s.

“Given these two developments, it is absolutely essential that we set aside business as usual and keep tight control over all other spending,” he added, repeating a demand the administration has often made of Congress.

Both the White House and the Congressional Budget Office say they expect annual deficits to continue for the next several years.