Government "confusion" over student funding and the prospect of tuition fees is putting students off access courses, according to City and Islington College, pioneer and one of the country's biggest providers of the one-year programmes.
Frank McLoughlin, director of the college's student services and learning resources, said applications for access courses at the institutions this year are "worryingly slow".
The college has been forced to scrap plans to expand its normal intake of 400 students on the programmes.
Mr McLoughlin said: "If recruitment is slow for us, I can assure you that it is slow for everybody else offering access courses."
The college won the Queen's Anniversary prize in 1995 for enabling students from disadvantaged backgrounds to progress to higher education. More than 90 per cent of its adult access students receive benefit. Around 350 of its access students went on to university last year.
Concern over recruitment levels led to the college sounding out potential access students.
"It is clear many are quite literally destabilised by the lack of coordination of funding policy by central government," says Mr McLoughlin.
Potential students are worried about having to pay tuition fees.
Tower Hamlet College is experiencing similar problems. Vice principal Judith Hinman said: "The whole funding muddle is deterring students.
"Many of them going on to university would be in poverty anyway and now it looks like they would face debt as well."
She warns that universities could find themselves seriously hit by a "drying up" of the access cohort.