A third of final-year university students would not have started degree courses if they had been forced to pay "top-up" fees, a study suggests.
Students will have to pay more for tuition from September
The UK Graduate Careers Survey findings are based on responses from more than 16,000 students at 30 universities.
Students in England will pay fees of up to £3,000 a year from September. The National Union of Students said this was deterring prospective students.
But ministers say poorer students will benefit from more generous grants.
The government has also insisted that students would benefit from not having to repay a loan until after they have graduated and have started work.
The Graduate Careers Survey report said 41% of finalists from state schools would never have gone to university if they had been faced with higher fees, compared to 38% of finalists in the survey overall.
Martin Birchall, managing director of High Fliers Research, which conducted the research, said: "These findings will be a major blow for the government."
Meanwhile, new figures released by the Universities and Colleges Admissions Service (Ucas) revealed that more than 14,000 fewer students applied for courses starting in September than at this time last year - a fall of 3.2%.
There were 424,560 applicants for a place, compared with 438,624 at the same point last year.
Despite being a fall, Ucas said there was no further percentage decline from the last statistics it released in February.
And Professor Drummond Bone, the president of Universities UK, said it was necessary to see the fall in applications "in the context of an overall upward shift over the last three years".
But NUS National President Kat Fletcher said the introduction of fees was deterring many.
"As we creep closer to September, we are getting more and more indications that top-up fees are impacting on student choice, and actually putting prospective students off university altogether," he said.
However, Higher Education Minister Bill Rammell said it was necessary to "concentrate on the facts".
He said: "Prospective students have known for some time about the new student finance arrangements, and while it's true that there has been a dip in applications, this is to be expected, given the much larger than usual increase in applications last year."
Prospective students based in England and applying to English institutions have fallen by 4%, in contrast to cross border applications from England to Scotland which increased by 1.8%.
Scottish applicants for places at Scottish institutions dropped by 1.3%, according to the figures.
And Welsh applicants hoping to study at institutions in Wales rose by 7.3%, whereas cross border applications from Wales to England have fallen by 5.2%.
In total, the number of applicants applying from the EU - excluding UK and Ireland - rose by 12.1%, while the number of overseas applicants - excluding EU and Ireland - fell by 6.3%.