Mature students fear the government's forthcoming review of student finance could drive tens of thousands of older learners away from higher education.
As education secretary Charles Clarke gave his clearest signal yet that a graduate tax is on the way, the Mature Students' Union warned that people aged over 25 were being overlooked. The MSU fears that the review will be biased towards the "traditional" 18-year-old undergraduate.
"Our voice is simply not being heard," said Alan Coleman of the MSU. The union is affiliated to 30 institutions, but says it represents all the country's 3 million mature students.
"One of the current proposals is a higher level of student loan. If that is accepted, more mature students will be forced out of higher education although no one is recognising this."
Students aged over 50 are not currently eligible for student loans, and Mr Coleman said that any increase in loans would inevitably lead to the cap being lowered to 45 years or even 40.
He said: "This has set alarm bells ringing for students and their families.
"Similarly, if there is a requirement to repay the loan and/or fees as a graduate tax then the student's remaining working life will inevitably be a factor, preventing more mature students from applying to university."
The union is calling for a return of the mature students' grant. It is urging the government to recognise that, unlike their younger counterparts, older learners are likely to have already incurred debts, including mortgages, and that many will be supporting dependants.
Mr Coleman said a further blow to mature students had been dealt by higher education minister Margaret Hodge's suggestion of a quota for younger students from poor backgrounds.
"The obvious knock-on effect is that higher education institutions will concentrate on this quota and supplement it with high income-providing students, again sidelining mature students," he said.
Older learners already faced a range of age-related discrimination after entering degree study, added Mr Coleman, including loss of pension entitlement and graduate employability.
He said that the government proposals appeared to contradict the forthcoming age discrimination legislation scheduled to be enacted by the end of 2006.
Mr Coleman said mature students were relieved they would no longer be required to pay upfront for their own and their children's education at the same time. But, he said, the possible alternatives and their consequences were now sinking in as yet another age-related barrier to education was put up.
"A cynic might suggest that this U-turn was the government's original plan and that top-up fees were merely a deliberately inflammatory proposal put forward to scare the public into accepting the equally unpopular graduate tax as the lesser of two evils," he said.
Christopher Gage, 38, is in the second year of an information technology degree at the University of East London.
He was made redundant from NatWest bank and had hoped to switch career to web design. But he had to stop attending lectures because he could not afford the daily £15 train fare to get to university.
He now works extra hours in a local pub to make ends meet. It is a vicious circle, he said, because he will have to repeat modules in the summer instead of earning much-needed cash.
Any increase in the student loan would be disastrous, he believes. "In future, the only older learners in universities will be those who can fund themselves 100 per cent."