Applications to postgraduate teacher training courses among those aged 22 and under have dropped compared to last year, according to official figures.
Statistics published by UCAS for training programmes starting in September, the number of applications by mid-July were 800 lower than at this point in last year's cycle – a 6.4 per cent drop.
In a blog analysing the figures, recruitment expert Professor John Howson said they showed that younger applicants were "deserting teaching".
"As remarked in previous months, it is the younger applicants that are deserting teaching," he writes. "There are 800 fewer applicants from those age 22 or under this year compared with 2016 and nearly 1,000 fewer than two years ago at this point in the cycle.
Professor Howson also said most "subjects have profiles below last year" in terms of offers, with music having the lowest July offers since 2013/14.
"All this does not bode well for providing teachers for a growing secondary school population in September 2018," he said.