THE INTEREST RATE on a key government-subsidized student loan doubled on Monday, an action that could potentially have a major impact on college-rich Massachusetts and the estimated 7 million students nationally who are scheduled to take out new loans for the coming school year.

The rate on so-called Stafford Loans is rising from 3.4 percent to 6.8 percent. For students who take out $25,000 in loans over a 10-year period, the change will increase the monthly payment from $250 to $300 and increase the total interest paid from $4,500 to $9,500. Two-thirds of college students typically take out some amount of student loan debt, which has surpassed $1 trillion in recent months.

Many expect Congress to return from its Fourth of July holiday break and tackle the student loan issue, perhaps on a retroactive basis, but there’s no guarantee the divided Congress will be able to reach any agreement before its August recess.

Katy Abel, a spokeswoman for the Massachusetts Department of Higher Education, said the higher interest rate would only put more pressure on college students struggling to make ends meet. “We’ve seen in the last year several of our public campuses opening food banks, which is an indication of how much financial stress students are already facing,” she said.

Bunker Hill Community College is one of the campuses in Massachusetts that has opened up food pantries for students, according to Bunker Hill spokeswoman Karen Norton. 

A number of legislative proposals have been put forward in the months leading up to today’s deadline. Some of them would continue the existing 3.4 percent rate, at least temporarily, while others would change the way rates are calculated.

Massachusetts Sen. Elizabeth Warren proposed legislation that would have charged students the same interest rate that big banks pay—0.75 percent—for government loans, but the measure failed to gain any traction.

“If we can invest in big banks by giving them low interest rates on their government loans, we should at least make the same investment in building a future for all our kids,” said Matt Cournoyer, Warren’s spokesman. 

On Thursday of last week, Sen. Joe Manchin, a Democrat from West Virginia, proposed a plan to allow the interest rates on Stafford Loans to change year to year based on conditions in the financial markets.

Although Manchin’s plan received support from Senate Republicans, Senate Majority Leader Harry Reid of Nevada strongly opposed the initiative because he said it does not provide students with enough rate stability. The plan, for example, has no cap on how high interest rates could climb.