Comments made last week by Nick Clegg, the deputy prime minister, suggest that the government is considering a new scheme to give ?2,500 a year in financial aid to all pupils on free school meals entering university.
Students would need to pass the English baccalaureate - at least a C grade at GCSE level in five core subjects - to qualify for the premium, details of which are "still under development", according to Mr Clegg.
However, with no new money apparently attached to the project, there are fears in the sector that existing funding body grants for widening participation might be raided to support the premium.
News of the scheme emerged in the same week as a letter from Vince Cable, the business secretary, and David Willetts, the universities and science minister, called on the Higher Education Funding Council for England and the Office for Fair Access to enact a "shared strategy for widening access to higher education".
Pointing to cash available under existing schemes, including Hefce's grant to improve widening participation, the letter asks how "record levels [of expenditure] might be best targeted to deliver impact".
"The time is now right to look strategically across investment streams, to ensure we achieve synergy and maximise outcomes for students," the letter says, urging "evidence-based assessment of what works in widening access".
Graeme Atherton, director of AccessHE, a widening-participation scheme in London, said that merging income streams may leave Hefce's premium - worth ?140 million in 2012-13 - vulnerable to cuts.
The "postcode premium" is allocated to universities based on the number of students they have from areas of low participation in higher education. Its biggest recipients are post-1992 universities, particularly those with large numbers of part-time students.
"Reading between the lines, (the letter) might be the first step to streamlining funding," Dr Atherton said. "The problem with the widening-participation premium is the evidence for its use is very thin. I'm not saying it hasn't been spent well, but there has never been much pressure to account for its use."
Pam Tatlow, chief executive of Million+, which represents many post-92 universities, said that if funds were concentrated on school-leavers through a student premium, it risked neglecting older students, who would not qualify.
"Supporting students of different ages and diverse educational backgrounds to succeed while they are at university is just as important as encouraging students to enter university in the first place," she said.
Linking financial support to the English baccalaureate would also shift resources from marginal pupils at poor schools to high-performing teenagers from poor backgrounds, argued Neil Harrison, senior research fellow in education at the University of the West of England.
"The scheme smacks of giving more to those students who are already achieving highly, and almost certainly going to university, rather than trying to encourage those that are marginal, who have had the misfortune to attend a poorly performing school," he said.