Universities and colleges should use private money to provide part-time courses for students from lower socioeconomic groups, say lawyers at the Southampton Institute.
David Bailey, who conducted a study on social inclusion and commercial diversification with Susan Barber, said: "Higher education has to be for everyone if we are to catch up economically. Universities have a moral duty to open their doors.
"Part-time degrees are central to widening participation, and we believe there is a growing market for them. Many institutions are discussing diversification of provision through greater links with local industry and commerce, and this is an opportunity to increase part-time provision."
Two weeks ago, the Higher Education Funding Council for England allocated money for 19,000 extra full-time places and 18,000 extra part-time places (9,000 full-time equivalent) for the coming academic year. However, the allocation has been attacked for failing to realise the potential of part-time education.
Geoff Peters, pro vice-chancellor of the Open University, said: "There seems to be a remarkable number of places going to full-time when part-time provision is known to enable access."
The OU asked for an extra 2,000 full-time equivalent places but was offered only 1,000. It is telling faculties to scale down the number of extra students they are aiming to recruit.
Mr Bailey and Ms Barber will present their paper Someone's knocking on the door at the Future Business of Higher Education conference at the University of Oxford next weekend. Analysis, pages 6 and 7, Leader, page 14