Washington (CNN) -- With time running out for Congress to prevent a doubling of interest rates on federal student loans, the White House and Republican leaders exchanged accusations Thursday on who was to blame for the lack of an agreement.
President Barack Obama chided Republicans for holding up a deal with unreasonable demands, and he urged college students to continue raising their voices on the issue.
However, spokesmen for Republican leaders in the House and Senate denied an assertion by press secretary Jay Carney that the White House has been working with them to try to reach a deal.
Asked about GOP complaints that the White House has not reached out to Republicans on the issue in recent days, Carney said that "we are actively working with members of Congress to get this done," adding, "in both parties."
Spokesmen for House Speaker John Boehner, R-Ohio, and Senate Minority Leader Mitch McConnell, R-Kentucky, disputed Carney's account.
On the Senate floor, McConnell accused Obama and Democrats of playing political games on the issue.
"It is the Democrat-led Senate that has failed to act and the president who has failed to contribute to a solution, and the reason is obvious," McConnell said. "It was reported yesterday that the Democratic Congressional Campaign Committee is launching a website with a student loan countdown clock aimed at raising money off this issue. The implication is that Republicans are the ones dragging their feet. "
The only reason the issue remains unresolved "is that the president wants to keep it alive," McConnell said, adding that "he thinks it benefits him politically for college students to believe we're the problem."
Despite such political back-and-forth, Senate Majority Leader Harry Reid, D-Nevada, said that "a series of meetings over the last 48 hours" with Republicans had raised hopes for a deal.
"At this stage, it appears that they are compromising, just as we are, and hope we can get something done," Reid said.
Leaders of both parties insist that they want to keep the federally backed rate at 3.4% for another year, but they sharply disagree over how to pay the $6 billion cost.
Democrats want to eliminate certain tax benefits for small-business owners, while Republicans want to cut a preventive-care fund created in 2010 as part of Obama's health care reform law.
The Republican-majority House has passed its version of the measure, which Obama has threatened to veto. The Senate continues to negotiate an alternative version.
If Congress fails to act by July 1, the rate jumps to 6.8%, with an average cost to students of $1,000 in increased loan debt, according to the White House.
In his remarks at the White House to students campaigning for an extension of the current rate, Obama blamed Republicans for preventing a deal.
"Last month, Democrats in the Senate put forward a plan that would have kept these rates in place without adding a dime to the deficit. Unfortunately, Senate Republicans got together and blocked it," Obama said.
"Over in the House, the Republicans said they'd keep these rates down only if we agreed to cut things like preventative health care for women, which obviously wouldn't fix the problem but would create a new problem," the president continued.
He also poked fun at an unidentified congressman, presumably Republican, who Obama said had warned that the student loan rate issue was about giving students "free college education."
That complaint "doesn't make much sense, because the definition of a loan is, it's not free; you have to pay it back," Obama said.
While Obama has repeatedly raised the issue in campaign appearances, certain GOP presidential nominee Mitt Romney has also said Congress should act to keep the rate at 3.4%.
In 2007, lawmakers temporarily cut the rate for undergraduates taking out federal Stafford loans up to the 2011 school year. The lower rates were phased in, so students have been able to access the lowest 3.4% rate on subsidized federal loans for only one school year.
The 2007 law allows interest rates to revert back to 6.8% for the 2012-13 school year, which starts in July.
CNN's Jessica Yellin, Alan Silverleib and Ted Barrett contributed to this report.