Even when lawmakers return, there’s no guarantee there will be the votes to restore the lower rates.
“When we pass a deadline and there are not immediate effects, the sense of urgency that accompanies a deadline evaporates, and that is what I’m afraid will happen here,” Mr. Hartle said.
For months, the student loan issue was the subject of partisan sniping — sometimes within the same party.
Mr. Obama’s budget proposal included a measure that would have linked student loan interest rates with the financial markets. Fellow Democrats called that unacceptable because there were no guarantees interest rates would not skyrocket if the economy improves.
The Republican-led House, meanwhile, co-opted the president’s proposal and passed a bill in May that linked interest rates to the financial markets but with a cap on how high rates could climb.
The Democratic-led Senate, meanwhile, tried for a two-year extension that failed to overcome a procedural hurdle. A Republican measure, similarly, came up short.
Top White House officials told allies to find any deal that could win enough votes and avert the politically and fiscally costly doubling.
An attempt at a bipartisan agreement fizzled last week when the chairman of the Senate education panel, Sen. Tom Harkin, Iowa Democrat, declared it a nonstarter and urged lawmakers to extend the rates for one more year — when they get back next week.
• Associated Press writer Stacy A. Anderson contributed to this article.