Student loan debt now exceeds total credit card debt, posing a potential major economic threat on par with the home mortgage crisis, according to a new report published by the National Association of Consumer Bankruptcy Attorneys (NACBA).

Nearly two out of five of bankruptcy attorneys (39 percent) have seen potential student loan client cases jump 25 to 50 percent in the last three to four years. And 95 percent of bankruptcy attorneys said that few student loan debtors are seen as having any chance of obtaining a discharge of those debts as a result of undue hardship.

Titled “Student Loan ‘Debt Bomb’: America’s Next Mortgage-Style Economic Crisis,” the NACBA study found that college seniors who graduated with student loans in 2010 owed an average of $25,250, up 5 percent from the previous year. Borrowing has grown far more quickly for those in the 35-49 age group, with school debt burden increasing by a staggering 47 percent.

The amount of student borrowing crossed the $100 billion threshold for the first time in 2010, and total outstanding loans exceeded $1 trillion for the first time last year.

Of the Class of 2005 borrowers who began repayments the year they graduated, one analysis found 25 percent became delinquent at some point and 15 percent defaulted. The Chronicle of Education puts the default rate on government loans at 20 percent.

The full survey questions and responses are set out in the survey report at www.nacba.org.