A report by the UK's higher education funding councils has criticised some universities for not attracting enough working-class entrants. How much of a problem is there and what is being done?
How many working-class people are going to university?
According to the latest figures, for entrants in 2001-2, 25.8% of university freshmen were from the three lowest social classes - up 0.4% from the previous year.
So, middle-class teenagers are still over-represented.
At Oxford and Cambridge, the proportion of working-class entrants was just 9%.
The funding councils have set targets or "benchmarks" for the number of undergraduates to be accepted from lower-income families.
In the UK as a whole, 28 institutions were described as significantly below target and 29 significantly above.
Among those failing most to attract working-class students were traditional universities, such as Oxbridge, Exeter, Bristol, Durham, St Andrews and Edinburgh.
What are the traditional universities doing to overcome this?
Most have set up programmes to target pupils in areas from which they do not attract many applicants.
Cambridge, for instance, has sent its Target Schools representatives to road shows around the country. It has also organised visits to colleges from pupils in deprived areas.
Earlier this year, public schools threatened to boycott Bristol University after it said it would take into account the "context" of applicants' previous education.
This led to claims of "positive discrimination" against wealthier pupils and of "social engineering" to adjust the class makeup of undergraduates.
The university denied a preference for either state or private sector applicants and the public schools dropped the boycott threat.
What does the government have to say about all this?
It says it wants more working-class students and to increase the number of young people going to university to 50% by 2010.
It has set up a task force under Professor Steven Schwartz, aimed at "widening access".
This week, Prof Schwartz discussed introducing a test similar to the US-style SATs.
Based on reasoning rather then classroom learning, these could give students whose A-level teaching had been poor a "second chance".
In other words, they would help universities choose entrants based on academic potential, as well as achievement.
Even if one agrees with the principle, which many educationalists do not, SATs are controversial in the US. Coaching for them has become a profitable industry, challenging the idea they are based solely on potential.
What else could be discussed by Professor Schwartz's taskforce?
One approach would be to make the university application process after exam results are known - which it is said would make a fairer system than the current process based on predicted grades.
Another idea used in the United States is to take a set quota of pupils from schools - so that bright youngsters in inner city schools have a guaranteed route into university.
But universities are likely to guard their independence jealously.
Will changing the university entry system really pull in more applications from poorer students?
The Conservatives have said that the real obstacle is not the admissions system, but the prospect of paying tuition fees, which they say they will abolish if elected.
There are also claims that the "blockage" in getting more students into university isn't at the age of 17 and 18, but earlier in the education system.
In particular, they say that too many pupils drop out of education at the age of 16.
And regardless of their social background, if youngsters stay at school long enough to get A-levels, they are likely to continue into higher education.
Out of all pupils who get two A-levels or more, 90% will have entered higher education by the time they reach the age of 21.
Many universities say it is the education system as a whole which is failing working-class children.