Heads of languages at dozens of top universities are calling on the government to reverse a decision allowing pupils to drop language study.
Universities say many pupils do not have the chance to study languages
University College London is even considering making it compulsory for new entrants to have a language GCSE.
The decision to make languages optional was made two years ago but the government has asked Lord Dearing to look at the decline in the subject.
GCSE results this year showed a drop in entries for modern languages.
Entries in German were down by 14.2% while French declined by 13.2%.
In an open letter to the Observer newspaper, which is also being sent to the Department for Education and Skills, 50 leading academics said the move to make languages optional embedded the notion that "languages do not matter, that English is enough".
One of the lead signatories of the letter, Nick Byrne at the London School of Economics, said students were often not being given the chance to study languages even if they wanted to.
He said he welcomed the expansion of teaching languages in primary schools but at secondary level many pupils were being "deprived" of learning languages because schools were effectively closing down language departments.
"When the obligation was removed I don't think the government thought that schools would think 'well, what's the point'," he said.
The complaint applies specifically to England but the issue is current across the UK.
The letter calls for languages to be a core subject up to the age of 16 in a format which suits the student.
Former education secretary Baroness Estelle Morris proposed the change to make studying a modern language at 14 to 16 optional.
She told BBC Radio 4's Today programme that schools could still choose to make language learning compulsory if it suited their local circumstances.
"The idea behind this decision was that government would not make every 15 and 16-year-old do a foreign language," she said.
She added that at the same time language learning in primary schools had been increased.
The Department for Education said it was awaiting Lord Dearing's findings - he is due to report on the issue within the next fortnight.
A spokesman said: "Any views expressed on the languages review will be taken into account when Lord Dearing makes his report to the secretary of state."