The weak economy will force Congress to raise the statutory debt limit this year, potentially setting up a touchy pre-election vote in the Senate but taking the issue off the new president’s plate.

Based on first-quarter economic data as well as the amount of tax revenue collected so far this year, the Treasury Department expects the debt ceiling will have to be raised before the end of the calendar year, Treasury spokeswoman Brookly McLaughlin said Thursday. She said the department did not have a timeline for when it would send a letter to Congress asking for the debt limit to be raised.

But lawmakers are primed to act.

“I have heard that there is going to be an additional need on the debt limit; we don’t have numbers that have been provided,” Senate Budget Chairman Kent Conrad, D-N.D., said. “I’m certainly not terribly surprised by this, given all the things that have happened.”

House Ways and Means Chairman Charles B. Rangel, D-N.Y., said he, too, expects Congress will have to move legislation this year to raise the ceiling.

“The indication from the leadership meetings is that we have to find some un-awkward way of doing that. I don’t know how, and [that] didn’t come up,” he said.

To avoid brushing up against the current debt limit, Congress would either need to act before leaving for the November elections or return for a post-election “lame duck” session.

Any measure addressing the debt limit offers both parties an opening to pillory the other’s fiscal record.

“Raising the debt limit always causes headaches, especially in an election year — no two ways about it,” said Paul D. Ryan of Wisconsin, ranking Republican on the House Budget Committee.

The issue is generally more painful for senators than House members.

Under the so-called Gephardt rule, the House will automatically pass legislation to increase the debt ceiling when a final budget has been adopted by both chambers. That rule is intended to help House members avoid the politically painful need to cast a vote on the issue, but the Senate has no similar rule. Its members usually face a recorded vote on the unpopular measure.

But raising the debt limit this year could take the issue off the plate of a new president, who Democrats heartily believe will be one of their own.

“We don’t want the new administration to have to face that,” Rangel said.

Budget leaders earlier this year expressed confidence that the government would not run up against the debt ceiling until early in 2009, even with the costs of the economic stimulus package (PL 110-185) that provided tax rebates to millions of Americans.

But congressional aides tracking the issue say the economic and fiscal picture has darkened since then, resulting in lower-than-expected revenue.

Congress raised the debt limit last year when it enacted, in late September, an $850 billion increase that pushed the statutory cap to $9.815 trillion (PL 110-91).

Timing is important. If the nation gets close to the debt limit near the end of the year, the Treasury would have much less flexibility to shift around assets and avoid a default by the government, because the department must make certain Social Security and Medicare trust fund payments at that time. A default would mean the Treasury could not pay interest on bonds and notes or borrow more funds.

The debt subject to the statutory limit includes government savings bonds, special securities held by trust fund accounts that finance government programs such as Social Security and Medicare, and publicly traded securities bought by Wall Street investors.

The House version of the budget resolution (H Con Res 312) calls for a $385 billion debt ceiling increase, but budget conferees may increase that amount when they reconcile the House measure with the Senate’s version (S Con Res 70).

The Senate appointed its conferees on the budget resolution late Thursday; the House appointed its own Wednesday night. A conference meeting on the budget is expected to take place next week and Congress is also likely to adopt a final budget blueprint next week as well.