A record number of students will be prevented from graduating this summer as universities introduce tough sanctions in response to non-payment of tuition fees.
A snapshot survey by The THES this week found that the worst hit institution, London Guildhall University, was owed £6 million in fees accrued over several years. The University of Central England is owed £1 million and many other institutions said they had substantial sums outstanding.
The National Union of Students said the practice of withholding final examination marks or barring student debtors from graduation ceremonies was unfair.
NUS welfare officer Verity Coyle said: "While we understand institutions are under great pressure, there are now more universities than ever planning to exclude students and we intend to oppose the practice vigorously.
"It is a short-sighted approach that badly affects morale on campuses. Ultimately universities will pay a high price for preventing students from graduating because it will put people off applying."
In previous years institutions have tended to make allowances for hard-up students, often making repayment schemes available and allowing debts to run beyond graduation. But new get-tough policies appear to be spreading. UCE has issued exclusion letters to 600 students warning them that they may not get their degrees if they fail to clear their debts.
Vice-chancellor Peter Knight said: "It is likely we will collect most of the money eventually but it is an enormous bureaucratic problem in having to constantly chase students and deal with problems of debt."
Baroness Warwick, chief executive of Universities UK, said there was no evidence of systematic non-payment of fees across the sector, although individual institutions had introduced a range of flexible methods to help students pay.
"This is an important income stream, worth £400 million in the current financial year," she said.
London Guildhall said that if students failed to pay their fees, they would be allowed to attend finals and papers would be graded as normal. But they would be excluded from the graduation ceremony and would not receive a paper record of their achievement, although the university would confirm marks by telephone.
Lincoln University said it was owed between £300,000 and £400,000 and students would not be allowed to graduate unless debts were paid.
Leeds University is chasing about the same amount as Lincoln, while at Newcastle University 62 students collectively owe £88,000 and will not be permitted to graduate unless they pay their fees. An additional £16,000 is owed by postgraduates at Newcastle.
De Montfort University estimates about 4,000 students owe it money. Most debts are for small items such as library fees, and De Montfort expects them to be settled. A spokesman said ten students would have awards withheld as a result of non-payment of fees.
Essex University is owed £26,000 by about ten students, while Sussex University said 18 students would not be able to graduate because of unpaid tuition fees.
Birmingham University said it was chasing fees and other debts from a handful of students, up to 20 of whom had received letters warning them of legal action.
Higher education minister Margaret Hodge said the students were breaking the contracts they had with universities and were putting their future at risk. "Graduates earn on average an extra £400,000 over their working lives compared with non-graduates. Higher education is a good investment. I hope that even at this late stage they will recognise and accept their obligations to pay their contributions," she said.
'No fee - no degree': how one student was penalised
Loughborough University English student Helen Jenkinson was nervous on results day, but when the notice went up and her name was not there, she quickly became hysterical.
"I looked down the list of fails, and when I wasn't there either I just didn't know what to think," she said. "I became hysterical very quickly. It seemed like the end of the world."
The university administration told Ms Jenkinson's head of department that there was an unpaid debt of £100 and that the results could not be released until it was paid and processed, which could take ten days. "It was just a bad joke," Ms Jenkinson said. "I had no idea I owed money to the university, it seemed as though the different departments were just not talking to each other."
Ms Jenkinson paid the debt at once, and her department took pity on her and relayed her results.