A bipartisan group of U.S. senators has written to the leaders of the Senate’s education committee warning them against slashing subsidies to lenders in the guaranteed-student-loan program.

The letter, which was signed by 14 senators — including Ben Nelson, Democrat of Nebraska, and Mel Martinez, Republican of Florida — was sent on Tuesday to Sen. Edward M. Kennedy, Democrat of Massachusetts, who is the committee’s chairman, and Michael B. Enzi of Wyoming, the committee’s top Republican, along with the Senate’s majority and minority leaders.

In the letter, the senators urge Mr. Kennedy and Mr. Enzi not to seek cuts in subsidies that could “destabilize the constructive balance” between direct lending and the guaranteed-loan program, also known as the Federal Family Education Loan Program, or FFELP.

Mr. Kennedy, who plans to introduce legislation in the coming days to reauthorize the Higher Education Act, has circulated a draft proposal that would wring more than $20-billion from the guaranteed-loan program through subsidy cuts and fee increases. If enacted, the subsidy cuts would come on top of $12.7-billion in cuts contained in last year’s deficit-reduction measure.

“We are concerned that recent budget and policy proposals could damage FFELP’s ability to continue to provide not only low-cost loans, but also the products, services, and technological innovations which have greatly improved the ability of American families to access and finance higher education,” the letter says. —Kelly Field