There are renewed concerns about a growing gender gap in higher education after figures again showed more women than men applying to university.
The gap in aspirations has been widening in recent years
Since 1998, 313,259 more women than men have made university applications.
The provost of University College London, Malcolm Grant, said the trend indicated a big fall in the number of university-educated men.
Universities were seeing the results of male educational under-achievement at earlier ages, he added.
Figures out this week show that by the mid-January deadline, 47,739 fewer men than women applied for university courses starting this autumn.
And the gap has widened: 10 years ago, 54% of university applicants were female. By this year the proportion had risen to 56%.
A decade ago, the numerical difference was just under 25,000. This year it was well over 47,000.
Mr Grant said: "I was aware that a gap has been growing but not what the extent of that was."
He said part of the reason was that many more women were now applying for courses which had traditionally been the preserve of men.
"I can remember when medicine was an unusual choice for a woman. Engineering is still a little behind, but in law women have for some time been in the majority."
But other factors were linked to boys' underachievement at school, ending in fewer boys than girls taking A-levels.
Mr Grant added: "We are only at the end of a long receiving line but it is having a very clear impact on the numbers and the proportion of each and we are concerned about that."
If the trend continued, there would be a very significant reduction in the number of men benefiting from a university education, he said.
Mr Grant said part of the answer lay in tackling boys' underachievement, particularly in lower income homes, and encouraging their aspirations.
Higher Education Minister Bill Rammell said the government was working hard to highlight the benefits to people's earnings and careers and raise their aspirations whatever their background or gender.
Previous analysis of young people entering higher education in 2001-02 had revealed that gender did not play a role in explaining participation, once prior educational attainment was taken into account, he said.
That was why work at school level to improve boys' attainment was so important.
"In the Pre-Budget Report, the chancellor announced an additional £10m in 2007-08 to develop more effective guidance to schools on improving boys' attainment.
"In addition the Department for Education and Skills has introduced a number of strategies to address the gap in gender achievement and to raise the performance of all pupils," Mr Rammell said.
A spokesman for the university admissions service Ucas said: "There could be a range of reasons why this gap occurs.
"More research needs to be undertaken in this area to fully understand this trend."