More students are dropping out of teacher-training courses - intensifying fears of a staff shortage.
Universities, already concerned that applications to teaching courses are slowing down, said this week that the proportion of students failing to finish their postgraduate courses has gone up from 10 to 14 per cent.
They blame the drop-outs on financial hardship and the fact that there are now more jobs available outside teaching.
The figures have been compiled by the Universities Council for the Education of Teachers which described them as "worrying and potentially very damaging". Independent calculations by the Higher Education Statistics Agency have confirmed the findings.
John Howson, a specialist in education statistics from Oxford Brookes University, said that student hardship could be to blame. "The fact that student teachers have to take on an extra 25 per cent of debt over four or five years of higher education - because of the postgraduate element - may be causing people to drop out. Students cannot afford to take that level of debt unless they can be confident their salary will cover it."
Mr Howson has alerted the teachers' pay review body to this issue. The review body has promised to consider it in time for next years' recommendations.
He also warned that starting salaries must not slip below the threshold for re-paying student loans. "What some people don't realise is that the interest on that loan is then compounded. To defer your loan is a disaster." Some other government trainees, he added, are treated more generously and receive a full salary.
The latest application figures for postgraduate certificate in education courses are still well down on last year. Mr Howson predicts that only three-quarters of the places in mathematics will be filled.
Maths is down from 1,056 to 721; science from 2,217 to 1,491; and languages from 1,503 to 1,322. Normally popular fields, English and history, are also showing a decline.
Other factors may be contributing to the slow down. More jobs are available outside teaching. BT has for example doubled this year's graduate training intake from 250 to 500 - and will require graduates skilled in maths and science.
There is also confusion about the bursary scheme for shortage subjects. The centralised hand-outs have been abolished and the grants will now be channelled through individual universities at their discretion. But the universities will not know how much money, if any, they have until next week.
Students may be waiting to see which training course offers the best deal, says Mr Howson. "The Government has abolished the old system in a very difficult year. It was not a very sensible decision."