Graduates from Oxfordshire are more than £100m in the red - amid fresh fears university debt is set to soar even further.

New figures show the average former student is £8,307 in the red, following the controversial introduction of top-up fees a decade ago.

In total, 13,000 graduates currently living in the county owe £108m, as of March this year.

But the totals are only the amount owed by those who have already completed their courses - excluding students hit by the hike in annual fees from £1,000 to £3,000 two years ago.

And they ignore any overdrafts run up with high street banks, or on credit cards, as students struggled to stay afloat.

Furthermore, the fee system is due to be reviewed next year, triggering fears the cap will be raised sharply - or scrapped together - as universities plead poverty.

Some leading universities want to charge £7,000 a year, arguing the current system leaves them unable to compete with top institutions in other countries.

The Liberal Democrats warned that today's students would pay a price for years to come from being burdened with unprecedented levels of debt.

Stephen Williams, the party's universities spokesman, said: "This will have a dramatic long-term effect on their ability to buy homes, start families and save for old age.

"Ministers must consider easing the burden on students whilst they are studying and re-consider how much students should be earning before having to repay their loans."

This month, the National Union of Students launched a campaign to warn that fees were widening divisions between rich and poor students, in a report entitled Broke and broken.

Those starting university this autumn are expected to owe more than £20,000 by the time they graduate. That debt will rise to £40,000 if fees are raised to £7,000, it is claimed.

However, ministers point out that loans are frozen in real terms - rising only in line with inflation - and that graduates taking out loans from this year can claim a repayment holiday of up to five years.

Bill Rammell, the higher education minister, said: "This autumn more students than ever before, two thirds of eligible new undergraduates, will be entitled to a non repayable maintenance grant of up to £2,835 a year.

"Together with loans available for tuition fees and living costs, and bursaries that universities offer, this improved package of support means nobody should be put off considering higher education for financial reasons."

Across England, £8.6bn is outstanding from loans and fees, the statistics released by the department for innovation, universities and skills (Dius) revealed.

Since 2005, anyone earning more than £15,000 must start repaying their debt. The Government expects most former students to clear their debts after 13 years.