Teenagers in some parts of England are up to 18 times more likely to go to university than their peers in other areas, a study suggests.
On average, around one in five youngsters born in England's poorest postcodes go on to higher education, compared to around half of those from homes in the wealthiest postcodes.
The new study, by education charity Teach First and the Credit Suisse EMEA Foundation, argues that poorer youngsters are still facing hurdles that their richer peers do not have to overcome, and calls for more action to boost the numbers of disadvantaged young people going on to study for a degree.
The findings come just days before teenagers across England, Wales and Northern Ireland receive their A-level results and learn if they have scored the grades they need for entry to their chosen degree course.
Using available data on university rates and socio-economic backgrounds, the study calculates that in some postcodes, such as parts of Derbyshire, as few as one in 20 youngsters go to university, whereas in other areas, such as parts of Buckinghamshire, this figure is as high as over 80%.
The study notes that universities and colleges have spent hundreds of millions of pounds on improving access to higher education, but argues that this money must be better targeted at "hard to reach" communities and young pupils.
It suggests that the Government should write off a proportion of student loans for teachers who commit to working in challenging areas, and that every school should have a clear careers strategy.
Teach First chief executive Brett Wigdortz, said: "There are still far too few disadvantaged pupils getting to university and completing their degree.
"They're simply not given the same chance to reach their full potential, with less access to brilliant teaching and less guidance on how they can turn their aspirations into reality."
Universities minister Jo Johnson said that recent UCAS data shows that disadvantaged pupils are more likely to go to university than ever before.
"Our higher education reforms will ensure universities look beyond just access - and focus on attainment, retention rates and readiness for the world of work," he said.