Students from the richest neighbourhoods are still almost 10 times more likely to go to a top university than those from the poorest areas.
And they are nearly three times more likely to study for a degree at all, according to new research by the Independent Commission on Fees.
It also reveals a widening gender divide, with more women going into higher education than men.
The new study analysed official data and statistics from the admissions service UCAS to look at different trends in university application and entry rates.
Overall, English 18-year-olds from the most advantaged backgrounds were 2.8 times more likely to go to any university than youngsters from the most disadvantaged areas, with 46.7% starting a degree compared to 16.9% of the poorest students.
This gap has closed slightly since 2010 when they were 3.2 times more likely to go into higher education, the findings show.
But the analysis reveals that the gap is wider for students going to leading universities.
English school leavers from the most advantaged areas were 6.8 times more likely to enter one of the 30 most selective institutions in the UK, and 9.5 times more likely to go to one of the 13 most prestigious universities, it found.
These splits have closed slightly over the last four years.
The study also found that across all universities, students who are not eligible for free school meals - a key measure of poverty - are still more than twice as likely to apply to go to university than those who are eligible for the dinners.
"The gap in application and entry rates between advantaged and disadvantaged students has narrowed slightly, but remains unacceptably large - particularly for the most selective universities," it concludes.
A poll conducted for the Sutton Trust on behalf of the Commission suggests that many people would be in favour of poorer students paying less for their university education.
Just over half (53%) of the 1,728 16-75-year-olds in England questioned backed the idea of students from lower income families being charged lower tuition fees, with 25% against the proposal.
The study examined gender differences and found that in 2013, 21% more 18-year-old women entered university than men of the same age.
It warns that the divide is largest among the poorest university applicants, with disadvantaged boys particularly under-represented.
Overall, the proportion of UK 18-year-olds taking up university places has recovered to above pre-2012 levels - the year fees were trebled to a maximum of £9,000.
Degree entry rates for English 18-year-olds were 2.9 percentage points higher in 2013 than in 2010, in Scotland they were 0.2 percentage points higher, in Wales 2.8 percentage points higher and in Northern Ireland 2.5 percentage points higher.
But it adds that the picture for mature and part time students is "much bleaker".
Applications from mature students in England are still considerably lower than pre-2012 levels, especially in England, it says, and there were 41% fewer part-time enrolments overall in 2012/13 than in 2009/10.
Will Hutton, chair of the Commission, said: "Whilst we welcome the recovery in the proportion of 18-year-olds taking up places at university after the introduction of higher fees in 2012, serious gaps in access to university remain.
"Our research shows that advantaged students are nearly 10 times more likely to attend a top university than their disadvantaged peers. Young men from disadvantaged areas are particularly badly affected and remain under-represented in applications to all universities."
A Business Department spokesman said: "It is encouraging that applications to higher education from 18-year-olds are at an all-time high - including the applications rates for young people from disadvantaged backgrounds.
"Prospective students recognise the lifelong value of a university degree, but we are not complacent and there is still more to do - particularly by some of the higher tariff institutions."
Professor Les Ebdon, director of fair access to higher education, said: "This comprehensive analysis shows that the new system of fees did not deter young people from disadvantaged backgrounds from applying to university.
"Disadvantaged young people are applying to, and entering, higher education at higher rates than ever before, which is excellent news.
"Despite this, the report shows that there is still an unacceptably large gap in participation rates between the most and least advantaged young people. This is especially the case in the most selective universities, although we have seen progress in recent years."
Paul Bridge, head of higher education at the University and College Union (UCU), said: " Since the introduction of £9,000 fees, we have seen a substantial drop in mature applicants, and the collapse of part-time entry, which has had a disastrous impact on widening participation and social mobility.
"We believe stronger demands must be made on universities, particularly those that are most selective, to diversify their intake. We need to see more pressure on universities to contribute to social mobility."
Dr Wendy Piatt, director general of the Russell Group, which represents 24 leading universities, said: "This report provides no evidence that higher fees have put off school leavers from going to university. In fact, the number of students on free school meals being admitted to the more selective universities rose by 22% last year.
"Russell Group universities are keen to ensure that anyone with the qualifications, potential and determination to succeed has the opportunity to study at a leading university, irrespective of their background.
"However, we must not lose sight of the bigger picture - progress continues to be limited by levels of achievement at school and a lack of advice on A-level subject choices."