James Coleman, chair of the University Council of Modern Languages, said that preliminary figures obtained from the Universities and Colleges Admissions Service show that acceptances to language degrees have dropped by more than 7 per cent compared with last year.
However, admissions are "very uneven" across the UK academy, with some institutions exceeding their recruitment targets while others struggle to fill places, said Professor Coleman, professor of language learning and teaching at The Open University.
Admissions to a language department at one Russell Group university, which he declined to name, fell by 20 per cent, he said.
And the intake at two new university departments fell even further, which could lead to the closure of some or all of their degree programmes, he warned.
"It could just be a blip, but our blip seems bigger than the average for other subjects," Professor Coleman said.
"Some Russell Group universities have recruited to target, others haven't, but several newer universities have also filled their spaces and could have taken more."
This year's reduction in student numbers continues the pattern of previous years, during which language provision has become "increasingly concentrated in Russell Group universities", he added.
Applied language degrees or those that combine languages with other subjects (such as business or law), programmes traditionally offered by more modern universities, have been particularly hit by closures in recent years, Professor Coleman said.
"The risk is that we lose the diversity within the sector and there is less choice for students. Losing degree programmes doesn't necessarily mean that languages will disappear from these universities. Students may still be able to do a language, but not as a full degree," he warned.
Languages were one of the subjects hardest hit by a 7.7 per cent decline in overall applications to UK universities this year, according to data released by Ucas in the summer.