Congress and the White House are driving up the deficit, alarming budget hawks as the government responds to the sputtering economy.

The nonpartisan Congressional Budget Office (CBO) has estimated that, for the first nine months of fiscal 2008, the government incurred a $268 billion deficit. That’s $148 billion more than a similar period last year — although about half that increase went toward economic stimulus checks. And much more spending is on the way.

But in an election year dominated by domestic concerns, and with the government moving aggressively to address the economy, attacking the swelling budget deficit is not high on the agenda of either party.

“When there is an economic downturn, as we’re experiencing, you expect deficits to jump,” said Sen. Kent Conrad (D-N.D.), chairman of the Budget Committee. “I think it would be very helpful if we were demonstrating something about the long term.”

Political rivals have engaged in election-year finger-pointing. The Bush administration blames Democrats for not dealing with the nation’s entitlement programs; Democrats on the Hill fault President Bush for the cost of the Iraq war.

The White House Office of Management and Budget (OMB) projected in February the country would have a $410 billion deficit at the end of fiscal 2008, but that will likely be a larger figure when it releases revised numbers later this month.

The national debt, which refers to the cumulative amount the government has borrowed and not repaid, is almost $9.5 trillion, the highest level in U.S. history, according to the Treasury Department.

The deficit is the amount of spending that exceeds tax revenue in a fiscal year.

Congress first responded to the turmoil in the financial markets by approving legislation in February that sent rebate checks to millions of Americans, driving up the deficit by $152 billion this year.

At least $14 billion worth of rebate checks had not yet been issued at the time of CBO’s latest projections, ensuring that the deficit will continue to increase. Also, Congress will likely approve an unpaid-for, one-year patch of the Alternative Minimum Tax that costs a little more than $60 billion, and might pass a package worth more than $50 billion in extensions of expiring tax incentives without raising taxes or cutting government spending.