More than a dozen leading institutions were criticised as figures showed they invested less than a fifth of available cash on subsidies for poor students, compared with almost 23 per cent of income at other universities.

The disclosure prompted fresh claims that working class teenagers could miss out on courses at England’s best universities following a hike in the cost of a degree.

Academics warned that the system risked descending into a "postcode lottery".

Since 2006, universities have been allowed to charge more than £3,000 a year in tuition fees. As a condition, they must set aside some of the additional cash on bursaries for the poorest undergraduates and promotional campaigns to attract applicants.

According to an official study published today, universities received some £1.3 billion in additional fee income last year, compared with £878 million a year earlier.

The monitoring report by the Office for Fair Access said universities spent almost 26 per cent – £344m – on bursaries and outreach, compared with 25 per cent – £219m – a year earlier. Last year's breakdown included 22.8 per cent on bursaries and a further 2.8 per cent on outreach campaigns.

But the National Union of Students criticised 15 of England’s top universities, including Bristol, King’s College London, Lancaster, Newcastle, Nottingham, Sheffield and York, for failing to do enough. They each invested less than 20 per cent on bursaries, according to Offa figures.

Aaron Porter, NUS president, said: “The regulation that surrounds the charging of top-up fees is farcical and has allowed greedy university heads with the worst record on access to ask for huge student contributions who then spend less on outreach than those with a better record at getting poorer students on to their courses.”

Currently, students from poor homes can claim grants directly from the state to help them through university.

Last year, they could receive a full grant of more than £2,800 if their parental income was less than £25,000 a year.

In addition, universities are supposed to provide a minimum bursary from their own funds of £310, although the average amount offered by institutions across England last year was £942, according to Offa.

Thames Valley University, west London, spent the most on bursaries (41 per cent), while Greenwich, south-east London, spent the least (7.7 per cent).

Sally Hunt, general secretary of the University and College Union, said: “How much financial support universities offer students is a complete lottery. It is ludicrous that students’ financial aid is decided in such a random and unfair way.

“Universities doing the most to attract students from the poorest backgrounds are unable to offer those students the vital funds they need to survive at university.”

But the Russell Group, which represents 20 top universities across the UK, insisted the amount of money invested by its members “greatly exceeded” the minimum requirement.

Wendy Piatt, director general, said: “Over 31,000 students from the very poorest backgrounds attending Russell Group universities received bursarial support averaging £1,523. This is nearly five times the minimum bursary of £310 required by Offa.”

She insisted that universities should be allowed to increase tuition fees above the current level of £3,290 when an independent review of charges is completed in the autumn.

“In the future, if they are to maintain world-class teaching, research and student support, universities must be allowed to increase the level of fees paid by graduates above current levels,” she said. “This would provide universities with more resources to recruit and support students from under-represented groups, and to ensure that all students, regardless of family background have fair access to the UK’s leading universities.”

Sir Martin Harris, director of Fair Access, said: "This continued level of expenditure demonstrates universities and colleges' strong ongoing commitment to widening access.

"In today's changed climate, it is imperative that universities maintain their commitment and continue to spend appropriate proportions of their additional fee income on access measures."

Source: Telegraph.co.uk