The following correction was printed in the Observer's For the record column, Sunday 19 September 2010

Tuition fees continued; a clarification: one of the case studies accompanying this special report on university finance implied that the student maintenance loan had to cover tuition fees as well. According to the Directgov website, there are two loans available for students: the tuition fee loan of £3,290 and the maintenance loan, which is a maximum of £4,950 if students live away from home during term time. Other factors, such as household income and where students live while studying, will affect the exact amount.

Thousands of students who receive donations from family and friends to help them through university would have dropped out of their courses without the handouts, a poll has found.

The survey of 3,863 undergraduates living in England reveals the extent to which students now rely on relatives and close friends to fund their degrees.

Almost half – 47% – of the students received financial help from their family and friends, compared with 39% two years ago. Some 60% of those that receive help said they would not be able to complete their degrees without the help of family and friends.

The survey, commissioned by the National Union of Students (NUS) and high street bank HSBC, also shows that students from wealthy homes are three times more likely to receive financial help from their families than those from the poorest households.

It comes ahead of a radical review of university financing due to be published in the coming weeks, and before the government's comprehensive spending review next month. Lord Browne, the former BP chief executive leading the review, is looking into whether tuition fees should rise above the current £3,290 per year and whether the amount students can receive in loans and grants should change.

Unpublished figures from the survey, which is run by the independent university guide Push, show that the average amount that university students owe their parents has risen to £903 this year from £890 last year.

Another study, of 11,000 teenagers hoping to study at university, showed that two-thirds expected to receive financial help. The president of the National Union of Students, Aaron Porter, said: "If the government misses this opportunity to implement a progressive funding system, it is clear that many young people, particularly those from poorer backgrounds with the ability and ambition to go to university, would have their opportunities restricted…For many students, the money they receive from family and friends is the difference between going to university or being shut out."

Sally Hunt, the general secretary of lecturers' trade union the University and College Union, said increasing the cost of a degree "might not make much difference to the millionaires in the cabinet, but would be a disaster for the majority of hard-working families in this country".

She added: "If you increase the cost of a degree, then people will think twice about whether or not to go to university and some simply will not be able to afford it at all. Politicians who are unable to recognise that expose themselves as massively out of touch with the real world and real people's concerns."