Official estimates suggest the amount of money loaned to students will balloon to a record level by 2047 before the Treasury starts to recoup the losses from graduates.
The disclosure – made in data obtained under the Freedom of Information Act – will raise fresh fears over the Coalition’s controversial higher education reforms.
Student leaders claimed the system would create a “debt time bomb that ticks for many decades”.
From next year, students starting degree courses in England will be charged up to £9,000 a year in annual tuition fees – almost three times the current total.
Ministers have pledged to provide undergraduates with subsidised loans to cover the cost of university fees and living costs. Graduates only start to make repayments when earnings hit at least £21,000 and outstanding loans are written off after 30 years.