Treasury officials are pushing ministers to cut funding for the teaching of poorer students, a university mission group has claimed.
Pam Tatlow, chief executive of the Million+ group of post-1992 universities, says moves are under way to reduce the widening-participation premium, worth £2 million in 2011-12.
The money is allocated by the Higher Education Funding Council for England to reflect the higher costs of teaching students from disadvantaged backgrounds.
Newer universities would be hardest hit by any reduction to the premium as they tend to have more part-time students or entrants from poorer backgrounds than the older institutions.
For instance, the University of Greenwich received about £5.1 million in widening-participation-related teaching money from the premium in 2010-11, Manchester Metropolitan University £4.9 million and Plymouth University £4.9 million, according to Hefce data. In contrast, the University of Cambridge picked up just £99,000, Imperial College London £62,000 and the London School of Economics £23,000.
"It has become clear in recent days that the Treasury thinks that cutting the widening-participation premium is a 'saving' worth making," Ms Tatlow said.
"The excuse is that more access funds will be available from 2012 as universities replace the outreach work previously undertaken by Aimhigher and also seek to mitigate the effects of higher fees with enhanced bursaries, scholarships and fee waivers." But she argued: "The Treasury's approach completely misses the point.
"Access funds support progression to university and seek to remove barriers for students who are most debt and risk averse. In contrast, the widening-participation premium contributes to the additional costs of teaching students from less traditional backgrounds once they enter university."
Concerns have been raised after David Willetts, the universities and science minister, failed to explicitly back the premium in the House of Commons on 8 December.
Asked by Julie Hilling, Labour MP for Bolton West, if the premium would be "fully funded in 2012, 2013 and beyond", Mr Willetts replied: "We have to look at the teaching grant year by year, so no assurances can be given about the total teaching grant at this stage."
He added that access funding will "increase significantly because of the increase in fees", with an extra £200 million committed to widening participation next year.
In July, however, Mr Willetts was clearer in his support for the premium. He told the Commons that the funding "is the equivalent of the pupil premium in schools" and "it is very important to reflect the additional costs that under-represented groups face".
A Hefce spokesman said the grant letter for 2012-13, due next month, would "give further guidance as to the priorities the coalition government would like the council to take into account when allocating funding".
He added that Hefce was "concerned to ensure that the progress made to date to improve the participation rates of students from groups under-represented in higher education continues to be supported".
It's not over yet: Working-class struggle continues, but women gain ground in post-war sector
The UK has made little progress since 1945 in increasing the proportion of working-class students going to university, an academic has claimed.
In a recent lecture titled "Widening Participation: The Post-War Scorecard", Malcolm Tight, professor in higher education at Lancaster University, gave Britain a score of just one out of five when it came to recruiting students from lower socio-economic backgrounds.
Speaking at a conference in Milton Keynes organised by the History of the Open University project, Professor Tight said the social background of students had not changed substantially.
"About a third of university students came from working-class backgrounds in the 1950s," he told Times Higher Education.
"When the Dearing report came out [in 1997], only 38 per cent of students came from lower socio-economic backgrounds.
"We can see we have hugely expanded the number of opportunities available and there are more students from lower socio-economic groups, but we are not recruiting a greater proportion."
However, his assessment of efforts to recruit more female, ethnic minority and mature students into higher education was far more positive.
He awarded Britain five out of five for increasing the educational opportunities available to women, although he acknowledged the shortage of female students in some subject areas and women's under-representation in senior academic posts.
Recruitment of ethnic minority students was given four out of five, with high participation rates undermined by the concentration of students at mainly urban, post-1992 universities.
Finally, Professor Tight awarded the UK three out of five when it came to increasing numbers of mature students.
He cited a 2006 report by Paul Ramsden, former head of the Higher Education Academy, which said there were a million part-time students, of whom half were aged 30 to 49. Their concentration in newer institutions and the treatment of part-timers by universities resulted in the lower score, Professor Tight said.